Depositing coatings on and within housings, apparatus, or tools utilizing counter current flow of reactants

ABSTRACT

A coating system for coating an interior surface of a housing comprising: first and second closures engaging first and second ends, respectively, of the housing to provide an enclosed volume; first and second flow lines coupled to the first and second closures, respectively, the first flow line and/or the second flow line connected to an inert gas source; a reactant gas source(s) comprising a reactant gas and coupled to the first and/or second flow line; and a controller in electronic communication with the reactant gas and inert gas sources, and configured to control flow of inert gas into the enclosed volume, and counter current injection of reactant gas from the reactant gas source(s) into the enclosed volume whereby introduction of pulse(s) of the reactant gas into the enclosed volume are separated by introduction of inert gas into the enclosed volume, and coating layer(s) are deposited on the interior surface.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of and claims priority to U.S.patent application Ser. No. 17/004,707 filed Aug. 27, 2020 and publishedas U.S. Patent Application Publication No. 2022/0062947, entitled“Depositing Coatings on and Within Housings, Apparatus, or ToolsUtilizing Counter Current Flow of Reactants,” which is herebyincorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to depositing coatings withinhousings, apparatus, or tools, such as well tools for use in a wellbore.More specifically, but not by way of limitation, this disclosure relatesto depositing coatings on one or more interior surfaces of a housing,apparatus, or tool, for example, well tools.

BACKGROUND

In applications, it can be desirable to deposit a coating on an interiorsurface of a housing, apparatus, or tool (e.g., within a well tool) towithstand a particular environment to which the surface will be exposedduring operation. For example, well tools for performing downholeoperations are often subject to internal corrosion and abrasion asfluids flow through the well tools. Fluids such as hydrogen sulfide andmercury can also chemically react with (or be absorbed by) the interiorsof the well tools. These destructive influences can reduce the lifespansof the well tools and cause a variety of other problems. A coating issometimes deposited on a surface to withstand such environments andprolong tool life.

BRIEF SUMMARY OF THE DRAWINGS

For a more complete understanding of this disclosure, reference is nowmade to the following brief description, taken in connection with theaccompanying drawings and detailed description, wherein like referencenumerals represent like parts.

FIG. 1A is a schematic diagram of an example of a coating systemaccording to some aspects.

FIG. 1B is a schematic diagram of an example of a well tool coatingsystem according to some aspects.

FIG. 2 is a generalized cross-sectional side view of an example of awell system with a well tool coating system according to some aspects.

FIG. 3 is a perspective view of an example of a tool (e.g., a well tool)and closures according to some aspects.

FIG. 4A is a flow diagram of a method of forming and using a pressurizedcell according to some aspects.

FIG. 4B is a graph of pressure within a cell as a function of timeduring formation and use of a pressurized cell according to someaspects.

FIG. 5 is a cross-sectional side view of an example of a tool (e.g., awell tool) with coatings according to some aspects.

FIG. 6 is a partial view of another example of a tool (e.g., a welltool) having multiple deposition chambers according to some aspects.

FIG. 7 is an exemplary schematic of a coating system configured foroperation, and depicted sealingly engaged, with a plurality of housingsaccording to some aspects.

FIG. 8 is a schematic diagram of an example of a well tool that can becoated via the well tool coating system according to some aspects.

FIG. 9 is a flow chart of an example of a process for depositingcoatings within housings, apparatus, or tools (e.g., well tools)according to some aspects.

DETAILED DESCRIPTION

It should be understood at the outset that although an illustrativeimplementation of one or more embodiments are provided below, thedisclosed systems and/or methods may be implemented using any number oftechniques, whether currently known or in existence. This disclosure,including the illustrative implementations, drawings, techniques andexemplary designs described herein, may be modified within the scope ofthe appended claims along with their full scope of equivalents.

Certain aspects and features of the present disclosure relate to ahybrid-type tool coating system (also referred to herein as a “coatingsystem” or “coating device” or simply “device”) and method fordepositing coatings on site, on (or more specifically inside of or on aninterior surface of, e.g., on a surface adjacent an interior volume of)a housing, apparatus, or tool (e.g., a well tool), optionally using oneor both of a chemical vapor deposition (CVD) process and an atomic layerdeposition (ALD) process. The coatings can resist physical wear on theinterior surface of the housing, apparatus or tool (e.g., well tool) dueto abrasive or corrosive elements flowing therethrough, enable theinterior surface of the housing, apparatus or tool (e.g., well tool) toresist chemically reacting with or absorbing fluids, and otherwise serveas a protective barrier to resist destruction of the interior surface ofthe housing, apparatus or tool (e.g., well tool). The disclosed aspectsof the coating system, as further detailed below, allow it to be madecompact and portable for enabling it to be used at any suitablelocation, such as at a jobsite, worksite, or wellsite, in a laboratoryenvironment, or elsewhere.

Any of a variety of housings, apparatus, or tools such as well tools(also referred to herein as wellbore tools or downhole tools) may havean interior surface on which to deposit a coating. Housings, apparatus,and tools such as well tools come in different shapes and sizes and alsomay have one or more passages connecting the interior region (alsoreferred to herein as an “interior volume” or simply “volume”) to otherregions inside the housing, apparatus, or tool (e.g., well tool) and/oran external environment outside the housing, apparatus, or tool (e.g.,well tool). In some examples of the present disclosure, an enclosedvolume or enclosed interior volume may be formed within a selectedhousing, apparatus, or tool (e.g., well tool) using a closure, which maycomprise one or more closure elements (e.g. plugs, gaskets, o-rings,non-circular sealing elements, threaded couplings, or any of a varietyof other ways to block and preferably to sealingly close off a selectedportion of one or more flow passages). The closure elements can have anysuitable shape configured to block and conform as required to openingsor passages leading into and out of the interior region of the housing,apparatus, or tool (e.g., well tool), to thereby enclose the internalvolume of the housing, apparatus, or tool (e.g., well tool) having theinternal surface(s) to be coated.

In some examples, the closure may be a single closure element thatcloses off a portion of an internal volume of the housing, apparatus, ortool (e.g., well tool), where the remainder of that internal volume is asealed volume as defined by the housing, apparatus, or tool itself. Inanother example, an internal portion of the housing, apparatus, or tool(e.g., well tool) having the surface to be coated may be open at bothends, and the closure may comprise two closure elements that close offthe internal volume at those ends. Any number (e.g. more than 2) ofclosure elements may be used to more specifically close off a portion ofthe housing, apparatus, or tool (e.g., well tool) to be internallycoated, particularly in the event of complex internal shapes where somefeatures are to be coated and other internal features are not to becoated (e.g. sensitive or non-metallic, non-wear features).

The closure elements may be structurally separate elements of a coatingsystem that are releasably secured to the housing, apparatus, or tool(e.g., well tool), or the closure elements may be permanently attachedto the housing, apparatus, or tool (e.g., well tool) and movable in andout of a closed position for closing selected internal locations of thehousing, apparatus, or tool (e.g., well tool). For purpose ofillustration, an example housing, apparatus, or tool (e.g., well tool)may have a cavity with a circular or other shaped cross-section, whichmay be closed off with a closure element at an upstream end and aclosure element at a downstream end, thereby enclosing a volume (e.g.,an “interior volume”) within the cavity between the upstream anddownstream closure elements.

In any given example, the enclosed volume may function as a de factodeposition chamber within the housing, apparatus, or tool (e.g., welltool) itself, into which one or more reactant gases and other gasesuseful in a coating process may be introduced, via a gas delivery system(i.e. gas supply system), as detailed hereinbelow.

At a high level, the gas supply system may comprise any of a variety ofmechanical flow control elements that fluidly couple the one or more gassources to the enclosed volume of the housing, apparatus, or tool (e.g.,well tool), such as any combination of supply lines, manifolds, valves,pumps, and/or other flow control element(s). The gas supply system canbe used to selectively couple selected ones of the plurality of reactantgas sources (or other process fluids) with the enclosed volume of thehousing, apparatus, or tool (e.g., well tool). The one or more gassources can include one or a plurality of reactant gas sources, one ormore buffer gas sources, one or more topical reagent sources, one ormore solvent sources, one or more oxidant sources, one or more etchinggas sources, or a combination thereof, as detailed further hereinbelow.

In one example, a supply line with a valve coupled between a reactantgas source and the enclosed volume may be used to selectively open orclose flow of that reactant gas source to the internal volume; andanother supply line and/or valve may be used to selectively open orclose flow of another reactant gas source to the internal volume, andthe gas supply system may be operated such that only the selectedgas(es) or other fluid(s) is/are supplied to the enclosed volume at anygiven time. One or more ports may be provided on the housing, apparatus,or tool (e.g., well tool) for selectively coupling the different gassources to the enclosed volume. Although not required, these ports maybe provided on the closure or closure elements themselves, such as afirst closure element with a port for coupling one or more gas sourcesto a first end of the enclosed volume of the housing, apparatus, or tool(e.g., well tool) and a second closure element with a port for couplingthe one or more gas sources to a second end of the enclosed volume ofthe housing, apparatus, or tool (e.g., well tool).

According to this disclosure, the controller is operably coupled to thegas supply system to control the flow of different gases (or otherfluids) to the enclosed volume having the surface to be coated. Thecontroller may be an electronic controller having control logic forcontrolling and optionally automating a sequence of gases, for processeslike ALD and CLD that entail a very specific sequence of reactant gasessuch as those example processes detailed below. According to thisdisclosure, the controller is in electronic communication with the oneor more (e.g., plurality of) reactant gas sources and the inert gassource, and is configured to control flow of inert gas from the inertgas source into the enclosed volume, and to control counter currentinjection of reactant gas from the one or the plurality of reactant gassources into the enclosed volume such that introduction of one or morepulses of the reactant gas into the enclosed volume are separated byintroduction of the inert gas into the enclosed volume, whereby one ormore coating layers are deposited on all or a portion of the interiorsurface within the enclosed volume.

In one application, once the deposition chamber (e.g., enclosed interiorvolume) is created as described above, a coating system can introducereactant gases into the deposition chamber (e.g., via pathways throughthe closures) in order to perform one or more surface coating processes.For example, the coating system can include a fluid delivery system,e.g. a gas supply system, for selectively supplying the reactant gasesto the deposition chamber inside the housing, apparatus, or tool (e.g.,well tool). As used herein, reactant gases are gases that chemicallyreact with a surface to produce a coating on the surface. Some examplesof reactant gases include, by way of example and without limitation,silane, methane, and carbon monoxide. Other examples are provided below.The coating system can contain sufficient reactant gases to perform botha CVD process and an ALD process inside the housing, apparatus, or tool(e.g., well tool), making it a hybrid system capable of performing morethan one type of surface coating process. The coating system of thisdisclosure includes the controller configured to control the fluiddelivery system (e.g., in order to apply the CVD process, the ALDprocess, or both) to the deposition chamber inside the housing,apparatus, or tool (e.g., well tool).

Creating the deposition chamber inside the housing, apparatus, or tool(e.g., well tool) can enable the coating system to be used at anysuitable location, without disassembling the housing, apparatus, or tool(e.g., well tool) into subcomponents and without the need for anexpensive commercial vacuum-chamber as the deposition chamber. Rather,some examples of the present disclosure enable a surface coating processto be applied to a housing, apparatus, or tool (e.g., well tool) locatedat a jobsite or worksite (e.g., a wellsite), as many times as desired(e.g., after each job using the housing, apparatus, or tool). Thecoating system can also cost less than traditional deposition systems,since forming a deposition chamber inside a housing, apparatus, or tool(e.g., well tool) can be cheaper and/or faster than installing acommercial-grade vacuum chamber at a manufacturing or laboratoryfacility, which may be governed by tight regulations and cleanroomrequirements.

The hybrid nature of aspects of the coating system can also promotesurface coating in challenging conditions, unlike traditional depositionsystems that only apply one type of surface coating process. Forexample, if an interior surface of a housing, apparatus, or tool (e.g.,well tool) is poorly conditioned for ALD due to damage or other factors,a coating system of the present disclosure can first apply a basecoating inside the housing, apparatus, or tool (e.g., well tool) using aCVD process to promote bonding during a subsequent ALD process. If aninterior surface of a housing, apparatus, or tool (e.g., well tool) ispoorly conditioned for CVD due to damage or other factors, the coatingsystem can first apply a base coating inside the housing, apparatus, ortool (e.g., well tool) using an ALD process to promote bonding during asubsequent CVD process.

In aspects, disclosed herein is a coating system for coating, with oneor more surface coating processes, an interior surface of a housingdefining an interior volume, the coating system comprising: a firstclosure and a second closure to sealingly engage with a first end and asecond end, respectively, of the housing to provide an enclosed volume;a first flow line fluidically coupled to the first closure and a secondflow line fluidically coupled to the second closure, wherein the firstflow line, the second flow line, or both are fluidically connected to aninert gas source; one or a plurality of reactant gas sources, whereinthe one or each of the plurality of reactant gas sources comprises areactant gas and is fluidically coupled to the first flow line, thesecond flow line or both; and a controller in electronic communicationwith the one or the plurality of reactant gas sources and the inert gassource, wherein the controller is configured to control flow of theinert gas from the inert gas source into the enclosed volume, and tocontrol counter current injection of the reactant gas from the one orthe plurality of reactant gas sources into the enclosed volume such thatintroduction of one or more pulses of the reactant gas into the enclosedvolume are separated by introduction of the inert gas into the enclosedvolume, and one or more coating layers are deposited on all or a portionof the interior surface within the enclosed volume.

Further disclosed herein is a method of coating, with one or moresurface coating processes, an interior surface of a housing defining aninterior volume, the method comprising: positioning the coating systemand a housing proximate each other, sealingly engaging the first closureto a first end of the housing and sealingly engaging the second closureto a second end of the housing to form the enclosed volume; countercurrently injecting the reactant gas from the one or the plurality ofreactant gas sources into the enclosed volume such that introduction ofone or more pulses of the reactant gas into the enclosed volume areseparated by introduction of the inert gas into the enclosed volume; anddepositing the one or more coating layers on all or a portion of theinterior surface within the enclosed volume.

In aspects, a method of coating an interior surface of a housingdefining a volume, can comprise: enclosing all or a portion of thevolume of the housing to yield an enclosed volume; introducing one ormore reactant gases to the enclosed volume via a plurality of inlets;and forming one or more coating layers on all or a portion of aninterior surface of the housing via atomic layer deposition (ALD) orchemical vapor deposition (CVD) of the one or more reactant gases,wherein a first reactant gas of the one or more reactant gases isintroduced into the enclosed volume counter currently from introductionof a second reactant gas of the one or more reactant gases into theenclosed volume.

These illustrative examples are given to introduce the reader to thegeneral subject matter discussed here and are not intended to limit thescope of the disclosed concepts. The following sections describe variousadditional features and examples with reference to the drawings in whichlike numerals indicate like elements, and directional descriptions areused to describe the illustrative aspects but, like the illustrativeaspects, should not be used to limit the present disclosure. The hereindisclosed coating system can be utilized to deposit one or more coatingson an interior surface of a housing, apparatus, or tool (also referredto both individually and collectively herein by any individual term“tool”, “housing”, or “apparatus”), for example as will be describedfurther herein with reference to FIG. 1A. Accordingly, the descriptionherein is thus applicable to generic coating systems for coating genericapparatus, housings, or tools. Likewise, the description herein isapplicable to, without limitation, specific uses such as, withoutlimitation, “well tool coating systems” and “well tools”, for example aswill be described further herein with reference to FIG. 1B. By way ofexample, the term “housing” includes, but is not limited to, astructural component having an interior volume such as (withoutlimitation) one or more components of an apparatus, device, or tool suchas a well tool. While certain description herein is made with referenceto well tools and well tool coating systems, in should be understoodthat the concepts disclosed herein are not limited to any specificembodiment such as well tools and well tool coating systems, but rathermay be applied generally to coating systems configured to effectivelycoat an interior surface adjacent an interior volume disposed within ahousing, or apparatus, via any of the various techniques (e.g., ALDand/or CVD deposition techniques) disclosed herein, or via anotherdeposition process adapted to employ counter current flow of reactantgas, as described herein.

FIG. 1A is a schematic diagram of an example of a coating system 200that can apply one or more coatings on or inside a generic housing,apparatus or tool 202, also referred to herein as a housing 202, anapparatus 202, or a tool 202. As noted hereinabove, a coating system ofthis disclosure can be utilized to deposit one or more coatings on orwithin a variety of housings, apparatus, or tools. One such embodimentis depicted in FIG. 1B, which is a schematic diagram of an example of acoating system 200A (also referred to herein as a “well tool coatingsystem 200A”) being utilized to apply one or more coatings on or insidea well tool 202A. Well tool 202A is usable for performing one or moredownhole operations, such as, without limitation, drilling, logging,fracturing, fishing, pulling, casing, cementing, or any combination ofthese or other downhole operation.

FIG. 2 is a generalized cross-sectional side view of an example of awellsite 100 at which a wellbore 102 is drilled through various earthstrata of a subterranean formation 104 bearing hydrocarbons. Thewellbore 102 is at least partially drilled and completed in thisexample, including a casing string 106 cemented within the wellbore 102that extends from the well surface 108 through at least a portion of thedrilled subterranean formation 104. The casing string 106 can provide aconduit through which produced formation fluids (e.g., productionfluids) can travel from downhole to the well surface 108. Without beinglimited to the particular features of the illustrated well, it should berecognized that well tools suitable for coating according to thisdisclosure may be involved throughout the process of initially drilling,forming, and completing the wellbore 102, and throughout the servicelife of the wellbore 102 and beyond. The wellsite 100 of FIG. 2 isillustrated by way of example as an onshore well system, although thedisclosure is equally applicable to wells formed offshore.

A coating system 200 according to this disclosure can be positioned at ajobsite (also referred to herein as a work site) for applying coatingson interior surfaces 229 of a housing, apparatus, or tool 202/well tool202A at the jobsite. The coating system or device 200 can apply thecoating(s) to the housing, apparatus, or tool 202/well tool 202A at anysuitable time, such as before the tool performs an operation, after thetool performs an operation, or both. As will be described furtherhereinbelow, the coating system 200 can be capable of applying thecoating(s) to the housing, apparatus, or tool 202/well tool 202A usingmultiple types of surface coating processes, such as ALD and/or CVD

For example and with reference to FIG. 1B, a well tool coating system200A according to this disclosure can be positioned at the wellsite 100(FIG. 2 ) for applying coatings on interior surfaces 229 of a well tool202A at the wellsite 100. The well tool coating system 200A can applythe coatings to the well tool 202A at any suitable time, such as beforethe well tool 202A performs a downhole operation, after the well tool202A performs a downhole operation, or both. The well tool coatingsystem 200A is capable of applying the coatings to the well tool 202Ausing multiple types of surface coating processes, such as ALD and CVD.

More specifically, in FIG. 1A/FIG. 1B, the tool 202/well tool 202A hasan interior region or interior volume 224 that is enclosed (e.g., at theends or two different locations thereof that are not necessarily ends ofthe tool 202/well tool 202A) by closures (including first closure 204 aon first end (or location) 205 and second closure 204 b on second end(or location) 207) in order to form an enclosed volume 226 (e.g., adeposition chamber) inside the tool 202/well tool 202A. The enclosedvolume 226 is bound on the sides (e.g., along length L thereof) by theinner perimeter (e.g., inner circumference or interior surface 229) ofthe tool 202/well tool 202A and at the ends by the closures (e.g., firstclosure 204 a and second closure 204 b). FIG. 3 is a perspective view ofan example of a housing, apparatus, or tool 202 (e.g., a well tool 202A)and first closure 204 a and second closure 204 b, according to someaspects. The closures (e.g., first closure 204 a and second closure 204b) can include closure elements, such as valves, gaskets, end caps, orany other sealing device of suitable shape and size to seal (e.g.,substantially seal) the interior region or volume 224 of the tool202/well tool 202A from the external environment outside the tool202/well tool 202A. In some examples, the closures (e.g., first closure204 a and second closure 204 b) are existing parts (e.g., disks,stoppers, plugs, caps, valves or gates) of the tool 202/well tool 202Arepurposed for creating the enclosed volume 226 therein. Alternatively,the closures (e.g., first closure 204 a and second closure 204 b) can bedistinct from the tool 202/well tool 202A, for example as shown in FIG.3 , and selectively secured to the tool 202/well tool 202A by a user(automatically or manually) to create the enclosed volume 226.

While the first and second closures 204 a/204 b are circular in FIG. 1A,FIG. 1B, and FIG. 3 , it will be appreciated by those of skill in theart and with the help of this disclosure that the closures (e.g., firstclosure/second closures 204 a/204 b) can have other shapes (e.g.,square, triangular, oval, or octagonal shapes) in other examples inorder to cooperate with tools 202/well tools 202A of other shapes.Likewise, although the tool 202/well tool 202A is depicted in FIG. 1A,FIG. 1B, and FIG. 3 to FIG. 7 as tubular, tools 202/well tools 202A comein a wide variety of shapes and configurations, and such tools haveinterior regions/volumes 224 for which it may be desirable to apply acoating. Consequently, the shape, location, and other characteristics ofthe enclosed volume 226 inside the tool 202/well tool 202A can varywidely depending on the type and configuration of the tool 202/well tool202A. For example, and without limitation, the enclosed volume 226 canbe relatively “long and skinny” or “long and narrow” which may bedifficult to coat via traditional coating techniques. For example, andwithout limitation, the enclosed volume 226 can have an aspect ratiothat is less than or equal to about 0.5, 0.05, or wherein the aspectratio is an average width W (e.g., diameter for cylindrical tools202/well tools 202A) of the interior volume 224 divided by an averagelength L thereof. The process of creating the enclosed volume 226 (e.g.,how the enclosed volume 226 is closed off from the external environmentand other regions of the tool 202/well tool 202A) can also vary widely,depending on the geometry of the tool 202/well tool 202A and theconfiguration of passages, openings, etc., leading into and out of thetool 202/well tool 202A.

Referring back to FIG. 1A/FIG. 1B, after the enclosed volume 226 (e.g.,deposition chamber(s)) is created inside the tool 202/well tool 202A,the coating system 200/well tool coating system 200A can apply one ormore coatings of material to interior surfaces 229 inside the tool202/well tool 202A using a fluid delivery system 208 and controller 206.The fluid delivery system 208 is coupled to sources 220 (e.g., tanks orcontainers) of gases (and optionally of other fluids) and the enclosedvolume 226 by conduit(s) or “flow line(s)”, such as first flow lines 228and second flow lines 227 (e.g., pipes, tubing, etc.). The fluiddelivery system 208 can selectively couple the sources 220 of gasesand/or other fluids (including reactant gas sources) with the enclosedvolume 226 to implement a surface coating process. Depicted in FIG. 1Aand FIG. 1B are reactant gas sources including first reactant gas sourceR1, second reactant gas source R2, third reactant gas source R3, andfourth reactant gas source R4, buffer or inert gas source B, oxidant gassource O, solvent source S, topical reagent source TR, etching gassource EG, and drying gas source D. The fluid delivery system 208 caninclude any suitable components, such as valves, manifolds, headers,and/or conduits, for controlling fluid communication there-through. Thefluid delivery system 208 can deliver the gases and/or other fluidthrough a valve or port in a first closure 204 a (e.g., one or morefirst closures 204 a) that allows the gases to enter the enclosed volume226 in a first direction as indicated by arrow A1 or through a valve orport in a second closure 204 b (e.g., one or more second closures 204 b)that allows the gases to enter the enclosed volume 226 in a seconddirection counter current to the first direction as indicated by arrowA2, while still otherwise closing off the enclosed volume 226 from theexternal environment. Alternatively or additionally, the fluid deliverysystem 208 can supply one or more gases and/or other fluids to theenclosed volume 226 through other access valve(s), port(s) or the likein the body of the tool 202/well tool 202A. With reference to FIG. 1Aand FIG. 1B, a coating device or system 200/well tool coating device orsystem 200A according to this disclosure for coating a surface 229 of aninterior region or volume 224 disposed within a housing or tool 202,wherein the interior volume 224 has a first end (or location) 205 andsecond end (or location) 207 and extends through the housing, apparatus,or tool 202/well tool 202A such that the interior volume 224 isaccessible from an exterior E of the housing, apparatus, or tool202/well tool 202A via the first end (or location) 205 and the secondend (or location) 207, can comprise: a first closure 204 a and a secondclosure 204 b to sealingly engage with a first end 205 and a second end207, respectively, of the housing, apparatus, or tool 202/well tool 202Ato provide an enclosed volume 226; a first flow line 228 fluidicallycoupled to the first closure 204 a and a second flow line 227fluidically coupled to the second closure 204 b, wherein the first flowline 228, the second flow line 227, or both are fluidically connected toan inert gas source B; one or a plurality of reactant gas sources 220(e.g., first reactant gas source R1, second reactant gas source R2,third reactant gas source R3, and fourth reactant gas source R4 depictedin FIG. 1A), wherein the one or each of the plurality of reactant gassources 220 comprises a reactant gas and is fluidically coupled to thefirst flow line 228, the second flow line 227, or both; and a controller206 in electronic communication (as depicted via dotted lines in FIG. 1Aand FIG. 1B) with the one or the plurality of reactant gas sources 220and the inert gas source B, wherein the controller 206 is configured tocontrol flow of the inert gas from the inert gas source B into theenclosed volume 226, and to control counter current injection of thereactant gas from the one or the plurality of reactant gas sources 220into the enclosed volume 226 such that introduction of one or morepulses of the reactant gas into the enclosed volume 226 are separated byintroduction of the inert gas B into the enclosed volume 226, and one ormore coating layers are deposited on all or a portion of the interiorsurface 229 within the enclosed volume 226. As discussed furtherhereinbelow, in aspects, the one or the plurality of reactant gassources are pressurized, e.g., pressurized cartridge(s).

The coating system can further include a plasma generator 210 configuredto generate a plasma and fluidically coupled to the (or another) flowline, such as first flow line 228 or second flow line 227; and one ormore pumps, such as a pump 214 fluidically coupled to the second flowline 227, the first flow line 228, or both and configured to create avacuum in the interior volume 226, said vacuum effective to draw one ormore reactant gases from the plurality of reactant gas sources 220 andoptionally plasma from the plasma generator 210 into the interior volume224 of the housing 202/well tool 202A via the first flow line 228 or thesecond flow line 227 and first end 205 or second end 207, respectively,such that, upon reaction of the one or more reactant gases, optionallyin the presence of the plasma, a coating is formed on all or a portionof the surface 229 of the interior volume 224 of the housing, apparatus,or tool 202/well tool 202A. As described further hereinbelow, thecoating device or system 200/well tool coating device or system 200A canfurther comprise an ion generator 222, configured for applying an atomiclayer etching (ALE) process to the surface 229; a heating unit 218 a inthermal communication with the housing, apparatus, or tool 202/well tool202A and in electronic communication with a controller 206 to controlheating of the housing, apparatus, or tool 202/well tool 202A; apreheater on a flow line, such as preheater 218 b on first flow line 228of FIG. 1A, in electronic communication with a controller 206 to controlheating of fluid (e.g., drying gas) introduced into the housing,apparatus, or tool 202/well tool 202A; and/or a trap 212 upstream of thepump 214 and downstream of the housing or tool 202/well tool 202A,wherein the trap 212 is operable as a filter and/or a second auxiliarycoating chamber. For example, trap 212 can be used as a filter prior tothe pump 214. Alternatively or additionally, a trap 212 (e.g., fromwhich ‘filter element(s)’ thereof have been removed) can be utilized asan auxiliary coating chamber. This auxiliary chamber can be utilized tocoat additional ‘pieces’ of the housing, apparatus, or tool 202/welltool 202A, for example, when these pieces are individual elements smallenough to fit into the trap 212 (e.g., tool windows, valves, plugs,etc.). In such instances, the pieces can be inserted within the trap 212for coating according to the methods described herein. Trap 212 can befluidically connected via a flow line 231 and a flow line 232 with afirst end 205 and a second end 207 of (e.g., a last) housing, apparatus,or tool 202/well tool 202A (in a series thereof). Line 233 can befluidically coupled with pump 214 for removal of unreacted reactants andinert gas passing therethrough.

As detailed further hereinbelow, the one or more surface coatingprocesses can comprise, without limitation, chemical vapor deposition(CVD), atomic layer deposition (ALD), or both. The coating device orsystem 200/well tool coating device or system 200A can be portable. Insuch embodiments, the coating device or system 200/well tool coatingdevice or system 200A can further comprises a portable conveyance orhauler (e.g., trailer, skid, vehicle, etc.) configured to transport thecoating device 200/well tool coating device or system 200A to a worksite(e.g., wellsite 100 of FIG. 2 ).

Controller 206 comprises control logic 230 designed to control flow ofthe inert gas from the inert gas source B into the enclosed volume 226,and to control counter current injection of the reactant gas from theone or the plurality of reactant gas sources 220 into the enclosedvolume 226 such that introduction of one or more pulses of the reactantgas into the enclosed volume 226 are separated by introduction of theinert gas B into the enclosed volume 226, and one or more coating layersare deposited on all or a portion of the interior surface 229 within theenclosed volume 226. For example, control logic 230 of controller 206can control introduction of a continuous flow of buffer gas from inertor buffer gas source B into enclosed volume 226 via first flow line 228or second flow line 228, and countercurrent introduction of pulses ofreactant gas from the reactant gas source(s) 220.

Coating, with one or more surface coating processes, the interiorsurface 229 of the housing 202 defining the interior volume 224according to this disclosure comprises: positioning the coating system200 and the housing 202 proximate each other, sealingly engaging thefirst closure 204 a to the first end 205 of the housing 202 andsealingly engaging the second closure 204 b to the second end 207 of thehousing 202 to form the enclosed volume 226; counter currently injectingreactant gas from the one or the plurality of reactant gas sources 220into the enclosed volume 226 such that introduction of one or morepulses of the reactant gas into the enclosed volume 226 are separated byintroduction of the inert gas B into the enclosed volume 226; anddepositing one or more coating layers on all or a portion of theinterior surface 229 within the enclosed volume 226.

In aspects, the coating system comprises the plurality of reactant gassources 220, one or more first flow lines 228, and one or more secondflow lines 227, wherein the plurality of reactant gas sources 220include one or a plurality of first reactant gas sources R1 comprisingone or more first reactant gases and one or a plurality of secondreactant gas sources R2 comprising one or more second reactant gases,wherein the one or each of the plurality of the first reactant gassources R1 are fluidically coupled to one of the one or more first flowlines 228 and wherein the one or each of the plurality of the secondreactant gas sources R2 are fluidically coupled to one of the one ormore second flow lines 227.

In aspects, one or more of the reactant gas sources 220 (e.g., firstreactant gas source R1, second reactant gas source R2, third reactantgas source R3, fourth reactant gas source R4, and optionally a topicalreagent source TR, an oxidant source O, a solvent source S, and/or anetching gas source EG, described further hereinbelow) comprisepressurized cells comprising the gas at a pressure of greater than thepressure of the enclosed volume, such as described, for example, in U.S.patent application Ser. No. 17/004,724 entitled “Depositing Coatings onand within Housings, Apparatus, or Tools Utilizing Pressurized Cells”,filed Aug. 27, 2020, the disclosure of which is hereby incorporatedherein in its entirety for purposes not contrary to this disclosure. Forexample, the one or the plurality of first reactant gas sources R1 cancomprise one or a plurality of first pressurized cells comprising afirst pressurized gas, wherein the first pressurized gas comprises theone or more first reactant gases and has a pressure of greater than thepressure within the enclosed volume, and the one or the plurality ofsecond reactant gas sources R2 can comprise one or a plurality of secondpressurized cells comprising a second pressurized gas, wherein thesecond pressurized gas comprises the one or more second reactant gasesat a pressure of greater than the pressure within the enclosed volume.The one or each of the plurality of first pressurized cells can befluidically coupled to the housing, apparatus, or tool 202 via a firstpressurized cell line comprising one of the one or more first flow lines228, and the one or each of the plurality of second pressurized cellscan be fluidically coupled to a second pressurized cell line comprisingone of the one or more second flow lines, such that one or more pulsesof the first pressurized gas can be introduced into the housing,apparatus, or tool 202 counter currently from introduction thereto ofone or more pulses of the second pressurized gas. For example, in suchaspects, the controller 206 can be in electronic communication with theone or the plurality of first pressurized cells R1 and the one or theplurality of second pressurized cells R2, and configured to controlinjection of one or more pulses of the first pressurized gas from thefirst pressurized cell into a flow of inert gas in the first pressurizedcell line (e.g., a first flow line 228) and one or more pulses of thesecond pressurized gas from the second pressurized cell into a flow ofinert gas in the second pressurized cell line (e.g., a second flow line227), such that the one or more pulses of the first pressurized gas andthe one or more pulses of the second pressurized gas are separatelyintroduced into the enclosed volume 226 with inert gas being introducedinto the enclosed volume 226 prior to and subsequent introductionthereto of each of the one or more pulses of the first pressurized gasand the one or more pulses of the second pressurized gas. In aspects,the coating system 200 comprises a plurality of first pressurized cells,a plurality of second pressurized cells, or both a plurality of firstpressurized cells and a plurality of second pressurized cells. Forexample, in aspects, one or more (e.g., all) of the first reactant gassource(s) R1, second reactant gas source(s) R2, third reactant gassource(s) R3, and fourth reactant gas source(s) R4 are pressurizedcells.

As depicted in FIG. 4A, a method of forming and using a pressurized cellaccording to this disclosure 500 can include forming the pressurizedcells at 510 and releasing one or more pulses of reactant gas from thepressurized cell into the housing, apparatus, or tool 202 at 520. Thecoating method of this disclosure can thus further comprise forming oneor more of the pressurized cells 510. As depicted in FIG. 4A, formingthe pressurized cell can include reducing a pressure of a cell to lessthan a vapor pressure of the reactant gas to be pressurized therein at510A, introducing the reactant gas into the cell at 510B, and increasingthe pressure of the cell to the pressure of greater than the pressurewithin the housing, apparatus, or tool 202/well tool 202A (e.g., to apressure of greater than pressure within enclosed volume/interior volumewithin housing, for example greater than atmospheric pressure) at 510C.Increasing the pressure of the cell to the pressure of greater than thepressure within the housing at 520C can include introducing ofadditional gas into the cell. The additional gas can comprise thereactant gas and/or an inert buffer gas. For example, the coating methodcan comprise forming one or each of a plurality of first pressurizedcells and/or one or each of a plurality of second pressurized cells byreducing a pressure of a cell to less than a vapor pressure of the oneor more first reactant gases and/or the one or more second reactantgases, respectively, introducing the one or more first reactant gasesand/or the one or more second reactant gases, respectively, into thecell, and increasing the pressure of the cell to the pressure of greaterthan the pressure within the enclosed volume via introduction ofadditional gas into the cell. The additional gas can comprise at leastone of the one or more first reactant gases and/or at least one of theone or more second reactant gases, respectively, or an inert buffer gas.FIG. 4B is a graph of pressure within the cell as a function of timeduring formation of a pressurized cell at 510 and use thereof at 520. InFIG. 4B, 1 depicts the pressure profile during step 510A of reducing apressure of a cell to less than a vapor pressure of the reactant gas tobe pressurized therein, 2 depicts the pressure profile during the step510B of introducing the reactant gas into the cell, 3 depicts thepressure profile during the step 510C of increasing the pressure of thecell to the pressure of greater than the housing pressure viaintroduction of additional gas into the cell, and 4 depicts the reducingpressure profile as pulses of the reactant gas in the pressurized cellare injected from the pressurized cell (e.g., the reactant gas sourcewhen it comprises a pressurized cell) into the pressurized cell line(e.g., one of the first flow line(s) 228 or second flow line(s) 227)during use of the pressurized cell at 520.

The pressurized gas in the pressurized cell can consist of or comprisethe reactant gas. For example, the first pressurized gas can consist ofthe one or more first reactant gases, or the first pressurized gas canfurther comprise from about 10 to about 90 volume percent (vol %), fromabout 20 to about 80 vol %, or from about 30 to about 70 vol % of abuffer gas; and/or the second pressurized gas can consist of the one ormore second reactant gases, or the second pressurized gas can furthercomprise from about 10 to about 90 volume percent (vol %), from about 20to about 80 vol %, or from about 30 to about 70 vol % of a buffer gas,and the like for reactant gas source(s) R3 and R4. The buffer gas in thepressurized cell(s) can be the same inert gas flowing (e.g., from buffergas source B) in the flow line (e.g., first flow line 228 or second flowline 227) via which the pressurized gas is introduced into the housingor tool 202, or can be a different gas. In aspects, the pressurized gascomprises from about 10 to about 5000 mg/cm³, from about 30 to about3500 mg/cm³, or from about 150 to about 1000 mg/cm³. The pressurizedcell can have any suitable volume, such as, for example and withoutlimitation, from about 10 to about 100 cm³, from about 10 to about 50cm³, or from about 20 to about 100 cm³.

The controller 206 can be configured to alternate introduction, into thehousing, apparatus, or tool 202, of one or more pulses of the firstpressurized gas with one or more pulses of the second pressurized gas.The one or more first reactant gases and the one or more second reactantgases can be the same or different. For example, the coating system 200of this disclosure can be utilized to provide counter current injectionof pulses of a reactant gas. That is, controller 206 can controlalternating injection of one or more pulses of a reactant gas intohousing or tool 202 via first end 205 by introduction of the one or morepulses of the reactant gas from a reactant gas source 220 into a flowingstream of inert gas in first flow line 228 with one or more pulses ofthe same or a different reactant gas from the same or another reactantgas source 220 into housing, apparatus, or tool 202 via second end 207by introduction of the one or more pulses of the same or the differentreactant gas from a reactant gas source 220 into a flowing stream ofinert gas in second flow line 227. In aspects, the one or more firstreactant gases and the one or more second reactant gases are the same,whereby one or more pulses of the same one or more reactant gases arealternately introduced into the enclosed volume 226 counter currentlyvia the first end 205 and the second end 207 of the housing or tool 202.Alternatively, the one or more first reactant gases and the one or moresecond reactant gases are different, whereby one or more pulses of theone or more first reactant gases can be alternately introduced into theenclosed volume 226 via the first end 205 counter currently with one ormore pulses of the one or more second reactant gases introduced into theenclosed volume 226 via the second end 207 of the housing, apparatus, ortool 202.

The pulses can comprise a desired amount of reactant per pulse. Forexample and without limitation, each of the pulses can comprise fromabout 1 to about 10 mg, from about 2 to about 9, or from about 3 toabout 7 mg of reactant.

The coating system 200 can further comprise: a heater, such as preheater218B; and a drying gas source D. The heater is in thermal communicationwith the drying gas source D, the housing, apparatus, or tool 202,and/or a line (e.g., a first flow line 228, as depicted in FIG. 1A, orsecond flow line 227) fluidically coupling the drying gas source D andthe housing, apparatus, or tool 202 such that a hot drying gas can beprovided within the enclosed volume 226 to dry the interior surface 229of the housing, apparatus, or tool 202 prior to introduction of reactantgas (e.g., any of the one or more first reactant gases or the one ormore second reactant gases, etc.) thereto. For example, preheater 218Bof FIG. 1A and FIG. 1B is depicted on first flow line 228, and can beutilized during drying of the interior surface 229 of the housing,apparatus, or tool 202 prior to introducing gas (e.g., any of the one ormore first, second, third, or fourth reactant gases from first, second,third, or fourth reactant gas sources R1, R2, R3, or R4, respectively,the etching gas from etching gas source EG, the oxidant from oxidant gassource O, the solvent from solvent source S, and/or buffer from buffersource B) into the housing, apparatus, or tool 202. In such aspects,controller 206 can be in further electronic communication with theheater 218B and/or the drying gas source D (e.g., via fluid deliverysystem 208) to control the heater 218B, and/or the drying gas source Dduring the one or more surface coating processes.

As noted hereinabove, the coating system 200 can further comprise one ormore pumps upstream or downstream of the housing, apparatus, or tool202. In some such aspects, the one or more pumps include a vacuum pumpon at least one of the one or more first flow lines 228, a vacuum pumpon at least one of the one or more second flow lines 227, or both avacuum pump on at least one of the one or more first flow lines 228 anda vacuum pump on at least one of the one or more second flow lines 227,wherein the vacuum pump is configured to create a vacuum in the enclosedvolume 226 during drying, whereby the one or more first flow lines 228or the one or more second flow lines 227 having the vacuum pump canoperate as a vacuum line. In such a manner, drying with the drying gasfrom drying gas source D can be effected via heating under vacuum.

A moisture detector 240 can be positioned on the vacuum line to measurea moisture content (e.g., dryness) of hot drying gas removed from theenclosed volume 226 during the drying. The method can comprise drying byproviding a hot drying gas in the enclosed volume 226, and monitoringthe drying by measuring a moisture content of the hot drying gas passingout of the housing, apparatus, or tool 202 during the drying. The methodcan comprise drying to a desired moisture content, such as a moisturecontent of less than or equal to about 0.01, 0.005, or 0.001 volumepercent (vol %) moisture. In aspects the moisture content of the hotdrying gas removed from the enclosed volume 226 during drying falls to avalue of less than or equal to about 0.001, 0.01, 0.1, or 1 volumepercent moisture prior to introduction of any reactant gas into thehousing or tool 202. The drying gas can be the same inert gas flowing inthe flow line into which the reactant gas is introduced from thereactant gas source 220, or a different gas. Desirably, the drying gasutilized for the drying has a purity (e.g., a non-water content or“dryness”) of greater than or equal to about 99.999, 99.99, 99.9, or 99volume percent.

The coating system 200 can further comprise a sensor for monitoring athickness of the one or more coating layers. For example such a sensorSA can be positioned on a first flow line 228 and/or a sensor SB can bepositioned on a second flow line 227. Each such sensor (e.g., sensor SA,sensor SB) can comprise a sensor for measuring a concentration ofuneacted reactants passing out of the enclosed volume 226, a quartzcrystal microbalance, or an optical monitor. In such aspects, thecontroller 206 can be in electronic communication with the sensor SA/SBand operable to adjust a duration of introduction of the reactant gas(e.g., the one or more first reactant gases and/or the one or moresecond reactant gases, etc.), an order of introduction of the reactantgas (e.g., the one or more first reactant gases and/or the one or moresecond reactant gases, etc.), a concentration of the reactant gas (e.g.,the one or more first reactant gases and/or of the one or more secondreactant gases, etc.) introduced into the enclosed volume 226, or acombination thereof. In such aspects, the method can further comprise:monitoring a thickness of the one or more coating layers being depositedduring the depositing, by measuring a concentration of unreactedreactant(s) (e.g., a concentration of one or more first reactant gasesand/or a concentration of unreacted one or more second reactant gases,etc.) passing out of the enclosed volume 226; measuring, via a quartzcrystal microbalance, a mass being deposited during the depositing; ormeasuring, via an optical monitor, the thickness of the one or morecoating layers being deposited; and controlling a duration of theintroducing of the reactant gas(es) (e.g., the introducing of the one ormore first reactant gases and/or the introducing of the one or moresecond reactant gases, etc.) into the enclosed volume 226, an order ofintroducing of the reactant gas(es) (e.g., the one or more firstreactant gases and/or the one or more second reactant gases, etc.) intothe enclosed volume 226, a concentration of the reactant gas(es) (e.g.,the one or more first reactant gases and/or of the one or more secondreactant gases, etc.) being introduced into the enclosed volume 226, ora combination thereof to optimize the depositing of the one or morecoating layers.

One example of a surface coating process that the coating system200/well tool coating system 200A can apply to an interior surface 229of the tool 202/well tool 202A is ALD. ALD can involve four main stepsthat are repeated to deposit a coating of a desired thickness on asurface: (i) a first step involving introducing a first reactant gasfrom a first reactant gas source into an enclosed volume 226 containinga surface (e.g., interior surface 229 which may or may not already havea coating layer thereupon) such that at least some of the reactant gaschemically bonds with the surface (e.g., interior surface 229 which mayor may not already have a coating layer thereupon) to form a reactivelayer, (ii) a second step involving removing leftovers of the firstreactant gas or gaseous byproducts produced during the first step fromthe enclosed volume 226, (iii) a third step involving introducing asecond reactant gas into the enclosed volume 226 such that at least someof this second reactant gas bonds with the reactive layer from the firststep to form a monolayer, and (iv) a fourth step involving removingleftovers of the second reactant gas or gaseous byproducts producedduring the third step from the enclosed volume 226. Some or all of thesesteps can be repeated as many times as is required to obtain the desirednumber of coating layers and the desired thickness of each layer.According to this disclosure, the first reactant gas and/or the secondreactant gas are introduced into the housing or tool 202 via countercurrent pulsing, and steps (ii) and (iv) are effected via introductionof the pulses in a flowing stream of the inert gas.

To implement an ALD process, the coating system 200/well tool coatingsystem 200A includes at least a first reactant gas, a second reactantgas, and a buffer gas (e.g., an inert gas such as nitrogen gas). Theseare provided in FIGS. 1A/1B as reactant gas source R1, reactant gassource R2, and buffer gas source B. Reactant gas and buffer gas can beused in the first step of the ALD process. The buffer gas (also referredherein to as inert gas) can be used alone in the second step of the ALDprocess (e.g., to purge the enclosed volume 226 of first reactant gas).The second reactant gas and the buffer gas can be used in the third stepof the ALD process. The buffer gas can again be used alone in the fourthstep of the ALD process. While this example involves using the samebuffer gas throughout the steps, other examples can involve usingdifferent buffer gases for various steps. Still other examples mayexclude the buffer gas altogether in some of the steps (e.g., steps twoand four) and/or use a pump 214 for performing these steps. For example,the well tool coating system 200 can include pump 214 (e.g., a vacuumpump) coupled to the enclosed volume 226 for suctioning reactant gases,gaseous byproducts, and/or buffer gases out of the enclosed volume 226(e.g., in order to implement the second and fourth steps of the ALDprocess). Also referred to as a “buffer gas”, the buffer gas in buffergas source(s) B can be used as a ‘carrier’ gas for first reactant gasand second reactant gas in steps (1) and (3), respectively, and as abuffer for steps (2) and (4). The same or different buffer gas(es), e.g.nitrogen (N₂), can be utilized in steps (1) and/or (3) as in steps (2)and/or (4). In aspects, the use of pressurized cells as gas sources canallow operation of the coating system at atmospheric pressure, in whichcase pump 214 may be absent.

The coating system 200/well tool coating system 200A can include anysuitable combination of reactant gases and buffer gases for performingthe ALD process. For example, the first reactant gases in first reactantgas source R1 and the second reactant gas in second reactant gas sourceR2 can include trimethyl-aluminum and ozone or water, respectively, forproducing coating layers of aluminum oxide inside the tool 202/well tool202A. Alternatively, the first and second reactant gases in firstreactant gas source R1 and second reactant gas source R2, respectively,can form coatings of titanium dioxide, hafnium dioxide, zirconiumdioxide, tantalum pentoxide, or other group IVB metal oxides and theirsilicate alloys, inside the tool 202/well tool 202A. In some examples,the inert or buffer gas from buffer gas source B can include nitrogen,helium, neon, xenon, argon, or any other inert gas that does notchemically react with the reactant gases and the surface 229 to becoated.

Still referring to FIGS. 1A/1B, another example of a surface coatingprocess that the coating system 200/well tool coating system 200A canapply to an interior surface 229 of the tool 202/well tool 202A is CVD.CVD can generally involve introducing at least one reactant gas into theenclosed volume 226 such that it chemically reacts with a surface (e.g.,interior surface 229 which may or may not already have a coating layerthereupon) inside the enclosed volume 226. In some examples, CVD caninvolve introducing two or more reactant gases simultaneously andcontinuously into the enclosed volume 226 such that they chemicallyreact with a surface (e.g., interior surface 229 which may or may notalready have a coating layer thereupon) inside the enclosed volume 226.

To implement the CVD process, the coating system 200/well tool coatingsystem 200A can include at least a third reactant gas, which isrepresented in FIG. 1A/1B as from third reactant gas source R3. Thecoating system 200/well tool coating system 200A may also include afourth (or more) reactant gas for implementing the CVD process. Thefourth reactant gas is represented in FIG. 1A/1B as fourth reactant gassource R4. The third and fourth reactant gases in third and fourthreactant gas sources R3/R4 can each include any suitable reactant gasfor performing a CVD process. For example, the third reactant gas or thefourth reactant gas can be configured to form coatings of carbide,silicon carbide, or aluminum oxide inside the tool 202/well tool 202A.The third/fourth reactant gases are stored in third and fourth reactantgas sources R3/R4, from which they can be supplied (e.g., via one ormore first flow lines 228 and/or second flow lines 227) to the enclosedvolume 226 inside the tool 202/well tool 202A.

According to this disclosure, the third reactant gas and/or the fourthreactant gas can be introduced into the housing or tool 202 via countercurrent pulsing.

As noted hereinabove, to control the surface coating processes, thecoating system 200/well tool coating system 200A includes controller206, that can be coupled to the fluid delivery system 208 by controllines 216 (shown in dotted lines in FIG. 1A and FIG. 1B). The controller206 is a physical device that can operate (e.g., the fluid deliverysystem 208) to control fluid flow into the enclosed volume 226 withinthe tool 202/well tool 202A. The controller 206 can be a mechanicalcontroller, a hydraulic controller, an electrical controller, or anycombination of these. In an example in which the controller 206 is amechanical controller, the control lines 216 can be links or cables andthe fluid delivery system 208 can include mechanically controlled pumps,valves, etc. In an example in which the controller 206 is a hydrauliccontroller, the control lines 216 can be hydraulic lines and the fluiddelivery system 208 can include hydraulically controlled pumps, valves,etc. In an example in which the controller 206 is an electricalcontroller, the control lines 216 can be wires and the fluid deliverysystem 208 can include electrically controlled pumps, valves, etc. Forexample, with reference to FIG. 1A and FIG. 1B, controller 206 can be inelectronic communication with fluid delivery system 208 and valves, suchas valve V1 on first flow line 228, valve V2 on second flow line 227,valve V3 on a line fluidically connecting first end 205 of housing 202with trap 212, and valve V4 on a line fluidically connecting second end207 of housing 202 with trap 212 to control the flow of fluidsthroughout coating system 200. Additional or fewer valves can beutilized, as will be apparent to those of skill in the art.

Controller 206 includes a processing device communicatively coupled to amemory device for executing control logic 230 stored on the memorydevice. Non-limiting examples of the processing device include aField-Programmable Gate Array (FPGA), an application-specific integratedcircuit (ASIC), a microprocessor, etc. The memory device can benon-volatile and may include any type of memory device that retainsstored information when powered off. Non-limiting examples of the memorydevice include electrically erasable and programmable read-only memory(EEPROM), flash memory, or any other type of non-volatile memory. Insome examples, at least some of the memory device can includes anon-transitory computer-readable medium, such as a magnetic disk, memorychip, read only memory (ROM), random-access memory (RAM), an ASIC,optical storage, or any other medium from which a computer processor canread the control logic 230, which can include program code forautomating a sequence of steps, including counter current reactant gasintroduction, for performing an ALD process, a CVD process, and/or anyanother surface coating process or processes.

The controller 206 can actuate the fluid delivery system 208 via thecontrol lines 216 to implement the ALD process, the CVD process, and/oranother surface coating process. For example, the controller 206 cansequentially actuate valves inside the fluid delivery system 208 suchthat first/second reactant gases from first/second reactant gas sourcesR1/R2 flow to the enclosed volume 226 in order to perform the ALDprocess. The controller 206 can also simultaneously actuate valvesinside the fluid delivery system 208 such that third/fourth reactantgases from third/fourth reactant gas sources R3/R4 flow to the enclosedvolume 226 in order to perform the CVD process. The controller 206 mayfurther control a pump 214 (e.g., a vacuum pump), which can suctiongases (e.g., reactant gases, buffer gases, byproduct gases) out of thetool 202/well tool 202A and optionally through a trap 212 that serves asa filter. Alternatively, the pump 214 can be separately controlledindependently of the controller 206. Controller 206 can also controldrying via electronic communication thereof with preheater 218B, heater218A, moisture detector 240, and drying gas source D.

The coating system 200/well tool coating system 200A can include othercomponents as well. For example, the coating system 200/well toolcoating system 200A can include a plasma generator 210 coupled to thecontroller 206, which can operate the plasma generator 210 to assist inperforming a surface coating process. The plasma generator 210 canconvert reactant and/or inert or otherwise non-reactive gases intoplasmas for performing a surface coating process. This may enablesurface coating to occur under a wider range of ambient conditions(e.g., temperatures and pressures) inside the enclosed volume 226 ascompared to a thermal approach. The presence of plasma may also enable awider range of material properties to be realized as compared to athermal approach employing other sources of heat (e.g., via heating unit218). In some examples, the plasma generator 210 includes a glass orquartz tube that serves as a plasma chamber and electrodes positionedwithin the plasma chamber. A direct current (DC) voltage can then beapplied to the electrodes that causes reactant gases (e.g., hydrogen,oxygen, ammonia, or silane) flowing there-through to be converted intoplasmas, which are then introduced into the enclosed volume 226. Theproperties of the plasmas can be tuned by adjusting the spacing betweenthe electrodes, the applied voltage, and the pressure inside the plasmachamber. In some examples, the plasma generator 210 can generatemicrowave plasmas, electron cyclotron resonance plasmas, orradio-frequency driven inductively coupled plasmas.

As noted above, the coating system 200/well tool coating system 200A caninclude a heating unit 218 coupled to the controller 206, which canoperate the heating unit 218 as part of performing a surface coatingprocess. One example of the heating unit 218 can be an oven or heatingjacket, which can receive the tool 202/well tool 202A and apply thermalenergy to the tool 202/well tool 202A in order to assist in performing asurface coating process.

The coating system 200/well tool coating system 200A may further includea solvent, an oxidizer, or both. These are represented in FIG. 1A/1B assolvent source S and oxidizer source O. The solvent is a substance thatcan dissolve another substance. Examples of solvents include toluene,xylene, benzene, carbon tetrachloride, tetrahydrofuran, dichloromethane,and d-limonene. The oxidizer is a substance that can oxidize anothersubstance (e.g., cause the other substance to lose electrons). Examplesof oxidizers include sulfur and nitrous oxide. The coating system200/well tool coating system 200A can operate the fluid delivery system208 to flush the enclosed volume 226 inside the housing, apparatus, ortool 202/well tool 202A with solvent S, the oxidizer O, or both. Thecoating system 200/well tool coating system 200A may flush the enclosedvolume 226 with one or both of these prior to performing a surfacecoating process in the enclosed volume 226. This can prepare theenclosed volume 226 for the surface coating process and help promotebonding.

In some examples, the coating system 200/well tool coating system 200Afurther includes one or more topical reagents. These are represented inFIG. 1A/1B as topical reagent source TR. A topical reagent is asubstance configured to chemically react with a coating layer depositedinside the enclosed volume 226 in order to change a materialcharacteristic of the coating layer. Examples of materialcharacteristics can include wettability, stiffness, strength, ductility,hardness, density, electrical conductivity, thermal conductivity, andcorrosion resistance. The coating system 200/well tool coating system200A can operate the fluid delivery system 208 to apply the topicalreagent from topical reagent source TR to one or more coating layersinside the tool 202/well tool 202A, thereby adjusting one or morematerial characteristics of the coating layer(s). As a particularexample, the coating system 200/well tool coating system 200A can applya topical reagent that includes hydrochloric acid to a coating layerinside the tool 202/well tool 202A. If the coating layer is formed fromhydrogen, the hydrochloric acid can burn off at least some of thehydrogen to improve the wettability of the coating layer.

The coating system 200/well tool coating system 200A can also includeone or more etching gases such as from etching gas source EG and an iongenerator 222 for applying an atomic layer etching (ALE) process insidethe tool 202/well tool 202A. ALE can be viewed as the reverse of thelayer deposition process of ALD, in the sense that ALE uses sequentialand self-limiting reactions to remove thin layers of material from asurface. The coating system 200/well tool coating system 200A canoperate the fluid delivery system 208 to apply the ALE process, forexample, in order to pre-treat the enclosed volume 226 prior to asurface coating process or to reduce the thickness of a coating layerresulting from a surface coating process.

ALE generally involves four main steps that are repeated: (i) a firststep involving applying an etching gas from etching gas source EG to asurface in an enclosed volume 226 such that the surface chemicallyreacts with and adsorbs the etching gas, and (ii) a second stepinvolving purging the etching gas and any gaseous byproducts resultingfrom the first step from the enclosed volume 226, (iii) a third stepinvolving applying low-energy ions to the portions of the surface thatchemically reacted with the etching gas in order to etch away (e.g.,remove) those portions, and (iv) a fourth step involving purgingbyproducts resulting from the third step. The controller 206 canimplement the first step by actuating the fluid delivery system 208 tosupply the etching gas from an etching gas source EG to within theenclosed volume 226. Examples of the etching gas can include argon,fluorine, chlorine, boron trichloride, and hydrogen bromide. Thecontroller 206 can implement the second and fourth steps by actuatingthe pump 214, actuating the fluid delivery system 208 to supply a buffergas (e.g., buffer gas from buffer gas source B) to within the enclosedvolume 226, or both of these. Alternatively, the etching gas can beintroduced as one or more pulses from etching gas source EG into aflowing stream of buffer gas, in a similar manner to that describedhereinabove for introduction of the reactant gas(es) into the housing,apparatus, or tool 202. The controller 206 can implement the third stepby actuating an ion generator 222, which can supply the low-energy ionsto the enclosed volume 226. Some or all of these steps can be repeatedas many times as is required.

While the coating system 200/well tool coating system 200A shown in FIG.1A/1B includes a certain amount and arrangement of components forillustrative purposes, other examples can include more, fewer, or adifferent arrangement of these components. For example, the coatingsystem 200/well tool coating system 200A can include more or fewercontrol lines, conduits (e.g., first flow lines 228, second flow lines227), reactant gases, buffer gases, topical reagents, solvents, oxides,etching gases, valves, or any combination of these. In one such example,the coating system 200/well tool coating system 200A only includes one,two, or three reactant gases (e.g., from a first reactant gas source R1,a second reactant gas source R2, and/or a third reactant gas source R3).At least one of the reactant gases (e.g., second reactant gas) can becommon to at least two surface coating processes. Also, some examplesmay exclude the plasma generator 210, the trap 212, the pump 214, theheating unit 218, the preheater 218B, the sensor SA, the sensor SB, themoisture detector 240, the ion generator 222, or any combination ofthese. Further, while some examples above are described in relation toALD and/or CVD, other examples can involve other types and combinationsof surface coating processes.

One example of the tool 202/well tool 202A after applying variouscoatings is shown in FIG. 5 , which depicts a partial view of the tool202/well tool 202A comprising a cylindrical housing having an interiorsurface 229. In FIG. 5 , the tool 202/well tool 202A includes anenclosed volume 226 with coatings deposited using different types ofsurface coating processes. In one example, the coatings include a baselayer 404 deposited onto interior surface 229 during a CVD process toimprove bonding with another coating layer 406 deposited onto layer 404during an ALD process. In another example, the coatings include a baselayer 404 deposited onto interior surface 229 during an ALD process toimprove bonding with another coating layer 406 deposited onto layer 404during a CVD process. Other examples can involve any number andcombination of coatings deposited (e.g., sequentially deposited to buildup a plurality of layers providing a desired coating thickness) usingany number and combination of surface coating processes. The base layer404 can be deposited directly onto an uncoated interior surface 229,optionally after cleaning and/or etching (e.g., ALE) thereof.

Still with reference to FIG. 5 , a cover 408 can be positioned insidethe enclosed volume 226 to prevent a surface coating process from beingapplied to a part 410 (e.g., a length or section) of the interiorsurface 229 of tool 202/well tool 202A. In some examples, the cover 408can include a metal plate or ring disposed over one or more grooves,collets, threads, or ridges inside the tool 202/well tool 202A toprevent one or more surface coating processes from being appliedthereto. For example, the cover 408 can be positioned to protect one ormore threads at one or more ends of the tool 202/well tool 202A frombeing damaged.

In some examples, the interior region or volume 224 of the tool 202/welltool 202A can include a movable part 414. Examples of the movable part414 can include a flap, valve, port, latch, pump, motor, tubular, ball,sleeve, piston, spring, seat, or any other component configured torotate, pivot, translate, or otherwise move inside the enclosed volume226. The movable part 414 can be actuated during a surface coatingprocess, for example, to ensure that one or more coatings are adequatelyapplied to the movable part 414. For example, a controller (e.g.,controller 206 of FIG. 2 ) can actuate the movable part 414 between atleast two positions during an ALD process, a CVD process, or both. Inone example in which the movable part 414 is a valve or port, the atleast two positions can include an open position and a closed position.In one example in which the movable part 414 is a latch, the at leasttwo positions can include a latched position and an unlatched position.In one example in which the movable part 414 is a flap, the at least twopositions can include various pivot angles. Any number and combinationof movable parts can be actuated between any number and combination ofpositions within the enclosed volume 226. By actuating the movable partduring or between coatings, an entire surface of the movable part 410that will come into contact with a fluid that can potentially becorrosive or otherwise interfere with the tool 202/well tool 202A (e.g.,interfere with a measurement obtained with the tool 202/wellbore tool202A) can be coated during the coating process. The movable part can bea sample probe (40, as described further hereinbelow with reference toFIG. 7 ), that can be coated in both an extended and a retractedconfiguration relative to a well tool 202A.

FIG. 6 is a partial view of another example of a tool 202/well tool 202Ahaving multiple passages (e.g., first passage 502 a and second passage502 b) therethrough. In one example, the passages (e.g., first passage502 a and second passage 502 b) are for providing different types offluid to tool 202/well tool 202A (e.g., downhole to a well tool 202A)and from tool 202/well tool 202A (e.g., from a well tool 202A to thewell surface 108 (FIG. 2 )). The passages (e.g., first passage 502 a andsecond passage 502 b) can be enclosed by closures 504 a-d (e.g.,including first closure 504 a, second closure 504 b, third closure 504c, and fourth closure 504 d), thereby forming multiple enclosed volumesinside the passages (e.g., first enclosed volume 226 a and secondenclosed volume 226 b). One or more surface coating processes can thenbe applied by the coating system 200/well tool coating system 200A tothe passages (e.g., first passage 502 a and/or second passage 502 b) tocoat them with layers of material. In the embodiment of FIG. 6 , firstclosure 504 a and second closure 504 b seal off passage 502 a to providefirst enclosed volume (or first deposition chamber) 226 a and thirdclosure 504 c and fourth closure 504 d seal off passage 502 b to providesecond enclosed volume (or second deposition chamber) 226 b. Theinterior surface 229 a of first enclosed volume 226 a and the interiorsurface 229 b of second enclosed volume 226 b can be coatedsimultaneously and/or sequentially utilizing the same or differentcoating processes (e.g., ALD and/or CVD), depending on the fluids towhich the interior surfaces are expected to be exposed during operationof the tool 202/well tool 202A during operation.

As noted hereinabove, a housing, apparatus, or tool 202/well tool 202Acoated via the coating system 200 of this disclosure can comprise anyapparatus, housing, or tool 202 for which a coating on an interiorsurface 229 thereof is desired. For example, and without limitation, thehousing, apparatus, or tool 202 can comprise a furnace tube, an aircraftcomponent (e.g., a wing, a fuselage), a component of a watersupply/treatment system; a component of a vehicle fuel system; a welltool 202A; a heat exchanger or component thereof such as a shell orplurality of tubes; a pump or component thereof such as a suction ordischarge chamber; a reactor or component thereof such as a vessel,manifold, catalyst bed, injector, feed and/or discharge conduit; adistillation column or component thereof such as valves or trays; acondenser or component thereof such as a housing or condenser tubes; areboiler or component thereof such as a housing or heating tubes; aninterior volume of a storage vessel; an interior volume of atransportation vessel (e.g., a fluid transport trailer pulled by a semitruck); or another housing, apparatus, or tool 202/well tool 202A.

In some embodiments, housing, apparatus, or tool 202 comprises a welltool 202A, and the coating system 200 is referred to herein as a welltool coating system 200A. For example and without limitation, the welltool 202A can comprise a logging tool or a wireline tool. For exampleand without limitation, the well tool 202A can be a drilling tool, suchas, without limitation, a logging while drilling (LWD) tool, ameasurements while drilling (MWD) tool, or a sampling while drilling(SWD) tool. In some such embodiments, the interior volume or region 224of the well tool 202A comprises a fluid flow path (or “flow passage”)configured for flow of a formation fluid from an exterior E of the welltool 202A through an interior (e.g., interior volume 224) of the welltool 202A.

The coating system can comprise or be configured for operation with aplurality of housings 202 connected in series and/or in parallel,wherein each of the plurality of housings 202 comprises a first closure204 a and a second closure 204 b to sealingly engage with a first end205 and a second end 207, respectively, of the housing 202 to provide anenclosed volume 226, and one or more first flow lines 228 fluidicallycoupled to the first closure 204 a and one or more second flow lines 227fluidically coupled to the second closure 204 b; wherein the second flowlines 227 fluidically coupled to each of the plurality of housings 202are fluidically coupled as the first flow lines 228 to any immediatelydownstream housing 202. In aspects, a plurality of n housings 202 areconnected in series. The plurality can comprise (i.e., n can be) fromabout 2 to about 30, from about 2 to about 15, or from about 5 to about10 housings 202. Each housing 202 _(x) of the plurality of housings 202except a last housing 202 _(n) of the series of housings 202 (i.e., allhousings 202 _(x), where x is 1 to n−1, from a first housing 202 ₁ to apenultimate housing 202 _(n−1)) is fluidically coupled with animmediately downstream housing 202 _(n+1) via a U-shaped connector. Oneor more of the U shaped connectors can be fluidically coupled with areactant gas source R (e.g., one of the plurality of first reactant gassources R1 and/or one of the plurality of second reactant gas sourcesR2, etc.), whereby the reactant gas(es) (e.g., the one or more firstreactant gases and/or the one or more second reactant gases, etc.) canbe injected into the one or more U-shaped connectors and therebyintroduced into the enclosed volume 226 of a housing 202 immediatelydownstream of the one or more U-shaped connectors.

FIG. 7 is an exemplary schematic of a coating system 200B configured foroperation, and depicted sealingly engaged, with a plurality of housings,apparatus, or tools 202. In the embodiment of FIG. 7 , three housings,apparatus, or tools 202, including a first housing, apparatus, or tool202A, a second housing, apparatus, or tool 202B, and a third housing,apparatus, or tool 202C, are depicted. For simplicity, the controller206 is not depicted. Coating system 200B can include a plasma generator210, an ion generator 222, a heater 218 a, and/or a pre-heater 218 b, asdepicted in FIG. 1A and FIG. 1B and described hereinabove. A number ofarrangements of reactant gas sources and housings, apparatus, or tools202 can be envisioned. Valving and fluid delivery system 208 can becontrolled via controller (206, FIG. 1A, FIG. 1B) to control flow offluids throughout the coating system 200B. For example, during a coatingprocess, inert gas can be continuously introduced into first flow line228A and first housing 202A by opening valves V1, V4, V5, and V6, andclosing valves V2, V3, V7, and V8 such that inert gas is introduced intofirst housing 202A via first closure 204 a thereof. The inert gas canflow through first housing 202A and out second closure 204 b of firsthousing 202A to second flow line 227A, which serves as first flow line228B of second housing 202B, via which inert gas flows into secondhousing 202B by way of first closure 204 a of second housing 202B. Thecontinuous flow of inert gas passes through second housing 202B andexits via second closure 204 b thereof and second flow line 227B, whichserves as first flow line 228C of third housing 202C, via which inertgas flows into third housing 202C by way of first closure 204 a of thirdhousing 202C. After passing through third housing 202C, inert gas canflow through second closure 204 b thereof, valves V6 and V4 and flowline 232, optionally into trap 212 and pump 214. A pulse of a desiredreactant can be introduced by opening the appropriate reactant gassource valve within fluid delivery system 208, whereby the pulse ofreactant gas is introduced into the continuous flow of inert gas andintroduced into first housing 202A. If desired, additional pulses ofthat desired reactant can be introduced into a housing 202 downstream ofthe first housing 202A. For example, one or more pulses of reactantintroduced into second housing 202B or third housing 202C, for exampleby manipulating valves for introduction into a connector between two ofthe housings 202 (e.g., by opening valve V2 and valve V7 andintroduction into a U-shaped connector 250A fluidically connectingsecond end 207 of first housing 202A and first end 205 of second housing202B, or by opening valve V8 and introduction into a second U-shapedconnector 250B fluidically connecting second end 207 of second housing202B and first end 205 of third housing 202C). Once the desired reactanthas reacted with the interior surface 229 of the plurality of housings,another reactant can be introduced counter currently into the housings,for example by closing valves V1, V4, V7, V8 and opening valve V2, V3,V5, and V6 such that inert gas is introduced continuously into thirdhousing 202C via second closure 204 b thereof and second flow line 227Cof third housing 202C. The inert gas can flow through third housing 202Cand out first closure 204 a of third housing 202C to first flow line228C, which is second flow line 227B of second housing 202B, via whichinert gas flows into second housing 202B by way of second closure 204 bof second housing 202B. The continuous flow of inert gas passes throughsecond housing 202B and exits via first closure 204 a thereof and firstflow line 228B, which is second flow line 227A of first housing 202A,via which inert gas flows into first housing 202A by way of secondclosure 204 b of first housing 202A. The inert gas passes out of firsthousing 202A via first closure 204 a thereof and, via open valve V3, canpass into trap 212, and/or pump 214 via flow line 231. A pulse of adesired subsequent reactant can be introduced by opening an appropriatereactant gas source valve of fluid delivery system 208, whereby thepulse of the desired subsequent reactant gas is introduced into thecontinuous flow of inert gas and introduced into third housing 202C. Ifdesired, additional pulses of the desired subsequent reactant can beintroduced into a housing now downstream of the first housing 202C inthis counter current flow regime. For example, one or more pulses of thesubsequent reactant can be introduced into second housing 202B or firsthousing 202A by manipulating valves for introduction into a connector(e.g., by opening valve V1 and valve V8 and introduction into U-shapedconnector 250B fluidically connecting second end 207 of second housing202B and first end 205 of third housing 202C, or by opening valve V7 andintroduction into U-shaped connector 250A fluidically connecting secondend 207 of first housing 202A and first end 205 of second housing 202B).Although a certain number of reactant gas sources 220 and housings 202are depicted in the Figures, it is to be understood that a coatingsystem of this disclosure can include any number of reactant gas sources220 for operation with any number of housings 202 connected in seriesand/or in parallel. One of skill in the art will appreciate that thereactant gas sources 220, and the housings 202 can be plumbed togethervia a multitude of valving arrangements, headers, connectors, or thelike to provide the herein disclosed novel counter current flow ofreactants during the coating process. All such arrangements are withinthe scope of this disclosure.

In aspects, each of the plurality of housings 202 comprises a cylinder,such as a wellbore tubular. Each of the cylinders can have a length in arange of from about from about 1 to about 10 feet, from about 2 to about9 feet, of from about 3 to about 8 feet, and/or an inside diameter(e.g., width W of FIG. 1A and FIG. 1B) of from about ¼ inch to about 10inches, from about ¼ inch to about 12 inches, or from about 1 inch toabout 15 inches.

In embodiments, a well tool 202A having an interior surface 229 coatedvia the well tool coating system 200A of this disclosure is a samplingtool, such as a focused sampling tool, such as described, for example,in U.S. patent application Ser. No. 16/670,886 entitled, “FocusedFormation Sampling Method and Apparatus”, filed Oct. 31, 2019, thedisclosure of which is hereby incorporated herein in its entirety forpurposes not contrary to this disclosure. FIG. 8 is a schematic diagramof an exemplary focused sampling well tool 202A that can be coated viathe well tool coating system 200A according to some aspects. Well tool202A of FIG. 8 is a focused sampling well tool operable to take one ormore fluid samples having a composition representative of a virginformation fluid in formation 104 (FIG. 2 ) in one or more samplechambers 90 (with five sample chambers, including first sample chamber90A, second sample chamber 90B, third sample chamber 90C, fourth samplechamber 90D, and fifth sample chamber depicted in the embodiment of FIG.8 ) from within the formation 104 (FIG. 2 ). A well tool 202A cancomprise a sample line 61; a guard line 51; a common line 71; a pump 75;a discard line 72; a sampling line 81; the one or more sample chambers90; one or more fluid ID sensors S positioned on the guard line, thesample line, the common line, or a combination thereof (with first fluidID sensor S1 and third fluid ID sensor S3 depicted on sample line 61,second fluid ID sensor S2 depicted on guard line 51, fourth fluid IDsensor S4 depicted on common line 71, and fifth fluid ID sensor S5depicted on pump outlet line 76); and a flow restrictor 55.

Sample line 61 has a sample line inlet 205B and a sample line outlet61B. Guard line 51 has a guard line inlet 205A and a guard line outlet51B. As depicted in the embodiment of FIG. 8 , a focused sampling welltool 202A of this disclosure can comprise one or a plurality of linesthat extend from guard line inlets 205A thereof and merge to form asingle guard line 51 toward guard line outlet 51B. This configuration ofguard line is intended to be included in the term “guard line(s) S1”. Inembodiments, the guard line(s) 51 is configured for a higher fluid flowrate Q_(G) than a fluid flow rate Q_(S) of the sample line 61. Commonline 71 has a common line inlet 71A and a common line outlet 71B, and isfluidly connected with the sample line outlet 61B and the guard lineoutlet 51B, for example at a tee or Y junction. Pump 75 has a suctionside inlet 75A and a discharge side outlet 75B. Suction side inlet 75Aof pump 75 is fluidly connected with common line outlet 71B anddischarge side outlet 75B of pump 75 is fluidly connected with discardline 72 and sampling line 81, for example via a tee or Y junction.Discard line 72 has a discard line outlet 207A. In embodiments, focusedsampling tool 202A of this disclosure comprises a single pump 75,whereby fluid is pulled into the well tool 202A via a common pump (e.g.,single pump 75) and a common suction line (e.g., common line 71).Sampling line 81 is fluidly connected with the one or more samplechambers 90.

Flow restrictor 55 is operable to prevent flow of fluid from guard line51 to common line 71 in a first (e.g., closed) configuration and allowflow of fluid from the guard line 51 to the common line 71 in a second(e.g., open) configuration. In embodiments, flow restrictor 55 is ashutoff valve. In embodiments, sample line 61 has a flow restrictorthereupon, such as restrictor valve VR, that is operable as a shutoffvalve that can be actuated to prevent fluid flow through sample line 61.In some such embodiments, a separate restrictor 55 may not be present.Flow restrictor 55 can be a check valve. Restrictor 55 can be positionedon guard line 51 upstream of guard line outlet 51B. Sample line 61 cancomprise a check valve upstream of sample line outlet 61B, inembodiments.

A focused sampling well tool 202A of this disclosure can furthercomprise a probe 40 that can extend from well tool 202A during formationsampling (as indicated by arrow A in FIG. 8 ) and define a sample zone60 fluidly connected with the sample line inlet 205B of the sample line61, a guard zone 50 fluidly connected with the guard line inlet 205A ofthe guard line 51, or both a sample zone 60 fluidly connected with thesample line inlet 205B of the sample line 61 and a guard zone 50 fluidlyconnected with the guard line inlets 205A of the guard line 51. Forexample, focused sampling well tool 202A of the embodiment of FIG. 8further comprises probe defining sample zone 60 fluidly connected withthe sample line inlet 205B of the sample line 61, and guard zone 50fluidly connected with the guard line inlets 205A of the guard line 51.The guard zone 50 and the sample zone 60 are in fluid communication withthe subsurface formation 104 (FIG. 2 ), during operation of the focusedsampling well tool 202A.

The comparative flow rate Q_(G) in the guard line(s) 51 from guardzone(s) 50 and flow rate Q_(S) in the sample line 61 from sample zone 60can be represented by a ratio of flow rates Q_(G)/Q_(S). (The flow rateinto the sample line 61 from the sample zone is represented by Q_(S),and is also referred to herein as the flow rate in the sample zone, andthe flow rate into the guard line(s) from the guard zone(s) 50 isrepresented by Q_(G), and is also referred to herein as the flow rate inthe guard zone(s).) The flow rate Q_(S) in the sample line 61 fromsample zone 60 may be selectively increased and/or the flow rate Q_(G)in the guard line(s) 51 from guard zone(s) 50 may be decreased to allowmore fluid to be drawn into the sample zone 60. Alternatively, the flowrate Q_(S) in the sample line 61 from sample zone 60 may be selectivelydecreased and/or the flow rate Q_(G) in the guard line(s) 51 from guardzone(s) 50 may be increased to allow less fluid to be drawn into thesample line 61 via sample zone 60. A focused sampling tool 202A cancomprise a single pump 75, a restrictor valve 55 and/or diameter ofsample line 61 and/or guard line(s) 51 can be selected to provide thedesired ratio Q_(G)/Q_(S) of fluid flow rate in the guard zone(s) 50 tothe fluid flow rate in the sample zone 60. In alternativeconfigurations, focused sampling tool 202A can comprise two or morepumps, for example a first pump coupled to sample line 61 and one ormore additional pumps coupled to guard line(s) 51, whereby the two ormore pumps can be operated independently to provide to provide thedesired ratio Q_(G)/Q_(S) of fluid flow rate in the guard zone(s) 50 tothe fluid flow rate in the sample zone 60.

A focused sampling well tool 202A can further comprise one or more deadvolumes 45 in fluid communication with the sample line 61. The one ormore dead volumes 45 can be online or offline dead volumes, meaningfluid in sample line 61 flows through the one or more dead volumes(“online”) or does not flow through the one or more dead volumes(“offline”) during a pre-sampling time period. As depicted in FIG. 8 ,the one or more dead volumes 45 can include a first dead volume 45A anda second dead volume 45B in series along the sample line 61. The one ormore dead volumes 45 provide a total dead volume V_(TOT). Inembodiments, the total dead volume V_(TOT) is greater than or equal to atotal sample volume of the one or more sample chambers 90.

Focused sampling well tool 202A can be operated to take one or morefluid samples (in the one or more sample chambers 90) from formation104, wherein the one or more fluid samples have a compositionapproximating that of a virgin formation fluid in formation 104.

Well tool coating system 200A can be utilized to coat an interiorsurface 229 extending from guard line inlet 205A and guard line 50and/or from sample line inlet 205B and sample line 61 to discard lineoutlet 72. For example, well tool coating system 200A can be utilized tocoat an interior surface 229 extending from guard line inlet 205A andguard line 50 and/or from sample line inlet 205B and sample line 61;optionally through the one or more dead volumes 45 (e.g., first deadvolume 45A and second dead volume 45B); through common line 71, pump 75,optionally sampling line 81, and discard line 72; to discard line outlet207A. Closures can be positioned on guard line inlets 205A and sampleline inlet 205B and on discard line outlet 207A, and surface coating(e.g., ALD and/or CVD) performed on all or a portion of the resultingenclosed volume 226 therebetween. During the forming of the coating,probe 40 can be extended from a retracted initial position or retractedfrom an extended initial position (e.g., respectively along or away fromthe direction indicated by arrow A) to ensure that an entire interiorsurface 229 that will be exposed to formation fluid during formationsampling can be coated. For example, the probe 40 may have telescopingportions of sample line inlet 205B and guard line inlets 205A that maybe extended and coated to ensure complete coating of the entire flowpath that will be in contact with the formation fluid during sampling.According to this disclosure, reactants can be introduced countercurrently via the guard line inlets 205A, the sample line inlet 205B,and the discard line outlet 207. That is the guard line inlets 205Aand/or the sample line inlet 205B can be utilized to introduce one ormore pulses of reactant(s), which can pass through well tool 202A, withunreacted reactant(s) and inert carrier gas exiting via discard lineoutlet 207A; and the discard line outlet 207A can be utilized forcounter current introduction of one or more pulses of the same or otherreactant(s), which can pass through well tool 202A, with unreactedreactant(s) and inert carrier gas exiting via guard line inlets 205Aand/or the sample line inlet 205B.

In some examples, one or more coatings can be applied within a tool202/well tool 202A in accordance with the process I shown in FIG. 9 .Other examples can include more steps, fewer steps, different steps, ora different order of the steps than is shown in FIG. 9 . The steps ofFIG. 9 are discussed below with reference to the components discussedabove in relation to FIGS. 1-8 .

As indicated at block 602, the method I can comprise creating one ormore enclosed volumes 226 inside the housing, apparatus, or tool202/well tool 202A. This may involve closing off one or more passages(e.g., first passage 502 a, second passage 502 b of FIG. 6 ) through thetool 202/well tool 202A by attaching closures (e.g., first closure 204a, and second closure 204 b of FIGS. 1A, FIG. 1B, and FIG. 3 , firstclosure 504 a, second closure 504 b, third closure 504 c, fourth closure504 d of FIG. 6 ) to first end or location 205 and second end orlocation 207 of the housing, apparatus, or tool 202/well tool 202A toform one or more enclosed volumes 226/226 a/226 b continuously spanninga length (e.g., the entire length) of an interior volume 224 of the tool202/well tool 202A. Alternatively, this may involve closing off one ormore passages through just a subpart of the tool 202/well tool 202A byattaching the closures (e.g., first closure 204 a, and second closure204 b of FIGS. 1A, FIG. 1B, and FIG. 3 , first closure 504 a, secondclosure 504 b, third closure 504 c, fourth closure 504 d of FIG. 6 ) tothe ends of the subpart, thereby creating one or more enclosed volumes226 continuously spanning only the length of an interior volume 224 ofthe subpart. That is, the closures need not be attached to the axial orradial ends or edges of the tool 202/well tool 202A (e.g., the threadedterminal ends of the tool 202/well tool 202A that may couple withadditional components such as a conveyance (e.g., drillpipe coupled towell tool 202A) or additional components of a downhole tool (e.g.,additional components of a bottom hole assembly comprising a focusedsampling well tool 202A) to form the one or more enclosed volumes226/226 a/226 b, but rather extend from one end of the passage toanother end of the passage, which passage need not continuously span theentire length or width of the tool 202/well tool 202A, but can extendfrom a first location 205 anywhere along a length of the tool 202/welltool 202A to another location 207 at a second (different) locationanywhere along a length of the tool 202/well tool 202A. After formingthe enclosed volume(s) 226, heat and/or pressure can be applied to theenclosed volume(s) 226 to create ambient conditions inside the enclosedvolume(s) 226 that are conducive to one or more surface coatingprocesses, such as ALD or CVD. For example, the pump 214 can pressurizethe enclosed volume(s) 226 to create suitable ambient conditions insidethe enclosed volume(s) 226 to perform one or more surface coatingprocesses as described herein. Alternatively, the pump 214 can be usedto evacuate all or portion of the enclosed volume 226, for example toaid in the introduction of one or more coating process reactant gases tothe enclosed volume 224. For example, heating unit 218 can be used tocontrol the temperature (e.g., heat) of the enclosed volume 226 tocreate suitable ambient conditions inside the enclosed volume(s) 226 toperform one or more surface coating processes as described herein.

As indicated at 604, the coating method can comprise drying the interiorsurface 229, as detailed hereinabove, prior to introducing any reactantsthereto. For example, drying can be effected via heating under vacuum,for example by introducing a drying gas from drying gas source D intohousing, apparatus, or tool 202, wherein the drying gas is heated by apreheater 218 b and/or the housing, apparatus, or tool 202 is heated bya heater 218 a, and hot drying gas is removed via second flow line 228.Moisture detector 240 can be utilized to monitor the drying process, anddetermine when sufficient drying of the interior surface 229 has beeneffected.

The method can comprise, as indicated at block 606, flushing theenclosed volume 226 with a solvent S, an oxidizer O, or both. Forexample, the controller 206 can operate the fluid delivery system 208 toprovide sequential or simultaneous flow of the solvent S, the oxidizerO, or both into the enclosed volume 226. This may help to prepare theenclosed volume 226 for one or more surface coating processes.

At block 608, the coating system 200/well tool coating system 200Adeposits one or more coatings within the enclosed volume 226 using oneor more types of surface coating processes including counter currentinjection of one or more reactants into the enclosed volume, as detailedhereinabove. For example, the controller 206 can operate the fluiddelivery system 208 to provide sequential or simultaneous flow ofreactant gases into the enclosed volume 226 in accordance with an ALDprocess, a CVD process, or both, as described hereinabove, to depositthe coatings. In other examples, the controller 206 can operate thefluid delivery system 208 to provide sequential or simultaneous flow ofreactant gases into the enclosed volume 226 in accordance with one ormore other types of surface coating processes to deposit the coatings.In embodiments, one or more of the reactant gases can be provided as aplasma produced in plasma generator 210.

The enclosed volume 226 can be configured to have certain ambientconditions that are more conducive to a surface coating process. Forexample, the enclosed volume 226 can be pressurized within a particularrange configured to produce viscous flow (rather than molecular flow) offluids therein, such as the reactant gases or buffer gases. Viscous flowis characterized by a Knudsen number, which is a dimensionless quantityof mean free path divided by a diameter of the flow channel (e.g., theenclosed volume 226). Knudsen numbers less than 0.01 characterizeviscous flow, whereas Knudsen numbers higher than 0.01 characterizemolecular flow. There is an inverse relationship between mean free pathand pressure. Based on these factors, the enclosed volume 226 can bepressurized to achieve viscous flow. For instance, a flow channel with adiameter of 0.5 centimeters (cm) yields a Knudsen number of about 0.001for nitrogen gas pressurized to 10 Torr. Decreasing the pressure to 1Torr yields a Knudsen number of 0.01. Any further decrease in thepressure below 1 Torr could further increase the mean free path and pushthe Knudsen number beyond the viscous flow regime and towards molecularflow. Thus, this flow channel can be pressurized between 1-10 Torr toachieve viscous flow. In aspects, one or more reactants utilized todeposit the coating layers at 606 are provided via a pressurized cell,as described hereinabove. In aspects, the interior surface 229 is coatedat a coating temperature of room temperature, a coating pressure ofatmospheric pressure, or both a coating temperature of room temperatureand a coating pressure of atmospheric pressure.

In aspects, the enclosed volume 226 can be configured to produce laminarflow (as opposed to turbulent flow) of the fluids therein. Laminar flowcan be achieved by configuring the enclosed volume 226 to have aReynolds number that is less than 2300. The Reynolds number is definedas the flow rate of the fluid times the diameter of the enclosed volume226, divided by the kinematic viscosity of the fluid and thecross-sectional area of the enclosed volume 226. Thus, in an example inwhich the diameter of the enclosed volume 226 is 0.56 cm and thekinematic viscosity for the fluid is 1.5×10⁻⁵ (m²/s), the upper bound onthe flow rate can be set to 150-200 scm to ensure laminar flow.

Reactant-gas dosing and purge times (e.g., timing between pulses ofreactant(s)) can be configured to optimize saturation (e.g.,self-limiting growth) during a surface coating process, while notwasting excess reactant gas or deposition time. For example,reactant-gas dosing times may range from 0.1 s to 1.0 s, and purgingtimes may range from about 5.0 s to about 10.0 s. This can result inrelatively constant ALD growth per cycle, even when more reactant gas isadded to the enclosed volume 226 or the purge time is extended.

As indicated at block 610, the process can comprise applying, via thecoating system 200 (e.g., well tool coating system 200A), a topicalreagent from topical reagent source TR to a coating layer within theenclosed volume 226 to adjust a material characteristic of the coatinglayer. The coating layer may be an uppermost coating layer in theenclosed volume 226. For example, the controller 206 can operate thefluid delivery system 208 to provide sequential or simultaneous flow ofthe topical reagent from topical reagent source TR into the enclosedvolume 226 to adjust a material characteristic of coating layer 406. Insome processes, applying a topical reagent at block 608 may be optionalor not required where a material characteristic of an uppermost coatinglayer does not need adjustment. In some processes, applying a topicalreagent TR at block 608 may be performed between on or more layers otherthan the uppermost coating layer. For example a topical reagent may beapplied after an ALD coating layer is applied and before a CVD coatinglayer is applied; a topical reagent may be applied after a CVD coatinglayer is applied and before an ALD coating layer is applied, orcombinations thereof.

Some or all of the above steps can be performed at a worksite orjobsite, such as, for example and without limitation, a wellsite 100.For example, the well tool coating system 200A can be positioned at thewellsite 100 for performing steps 602-610 after delivery of the welltool 202A to the wellsite 100 and prior to positioning the well tool202A downhole. Some or all of the above steps can also be repeated, forexample, in instances where there are multiple enclosed volumes insidethe well tool 202A. Some or all of the above steps can also be repeated,for example, in instances where a well tool 202A is recovered from beingdeployed downhole, and while downhole an interior surface of the welltool 202A was exposed to formation fluid, wherein the process asdepicted in FIG. 9 can be used to coat and/or re-coat all or a portionof the interior surface of the well tool 202A that was exposed to theformation fluid. In aspects, the first reactant gas source R1 and thesecond reactant gas source R2 are pressurized cells. In such aspectspump 214 may be absent.

In block 612, the tool 202/well tool 202A is positioned in an operatingenvironment. For example, when housing, apparatus, or tool 202 comprisesa well tool 202A, block 612 can comprise positioning the well tool 202Ain the wellbore 102 (FIG. 2 ). For example, the well tool 202A can bepositioned downhole using any suitable type of conveyance, such as adrillpipe, wireline, slickline, or coiled tubing. The tool 202/well tool202A can then be utilized to perform one or more operations. Forexample, the well tool 202A can then be used to perform one or moredownhole operations, such as, without limitation, formation fluidsampling.

In aspects, a method of coating a surface 229 of an interior region orvolume 224 of a housing 202, wherein the interior volume 224 has a firstend 205 and a second end 207, comprises: positioning the coating deviceor system 200 as described hereinabove and the housing, apparatus, ortool 202/well tool 202A proximate each other; sealingly engaging thefirst closure 204 a to the first end 205 of the interior volume 224 ofthe housing, apparatus, or tool 202/well tool 202A and sealinglyengaging the second closure 204 b to the second end 207 of the interiorvolume 224 of the housing, apparatus, or tool 202/well tool 202A toprovide enclosed interior volume 226; counter currently injecting thereactant gas from the one or the plurality of reactant gas sources intothe enclosed volume 226 such that introduction of one or more pulses ofthe reactant gas into the enclosed volume 226 are separated byintroduction of the inert gas into the enclosed volume 226; anddepositing the one or more coating layers on all or a portion of theinterior surface 229 within the enclosed volume 226.

In aspects, a method of coating an interior surface 229 of an interiorvolume or region 224 of a housing 202, wherein the interior volume orregion 224 has a first end 205 and a second end 207, comprises:enclosing all or a portion of the interior volume 224 of the housing,apparatus, or tool 202/well tool 202A to yield an enclosed volume 226;introducing one or more reactant gases, plasma, or both to the enclosedvolume 226; and depositing one or more coating layers (e.g., base layer404 and another coating layer 406 of FIG. 5 ) within the enclosed volume226 (e.g., on all or a portion of the interior surface 229 of theenclosed interior volume 226 of the housing, apparatus, or tool 202/welltool 202A) via one or more surface coating processes employing countercurrent injection of reactant gas(es) into the enclosed volume 226. Theinterior volume 224/enclosed interior volume 226 can comprise a fluidflow path of the tool, apparatus, or housing, apparatus, or tool202/well tool 202A.

As detailed hereinabove, the depositing at 608 can comprise chemicalvapor deposition (CVD), atomic layer deposition (ALD), or both. Forexample, in embodiments, the method can further comprise: forming an ALDlayer by: (i) introducing a first reactant gas from a first reactant gassource R1 into the enclosed volume 226, such that at least a portion ofthe first reactant gas chemically bonds with the surface 229 to form areactive layer; (ii) removing unreacted first reactant gas and/orgaseous byproducts from the enclosed volume 226; (iii) introducing asecond reactant gas from a second reactant gas source R2 into theenclosed volume 226, such that at least some of the second reactant gasbonds with the reactive layer to form an ALD layer; and (iv) removingunreacted second reactant gas and/or gaseous byproducts from theenclosed volume 226. Some combination of (i) through (iv) may beutilized to form the ALD layer. For example, not all of (i) to (iv) needbe utilized during the forming of the ALD layer.

For example and with reference now to FIG. 1A and FIG. 1B, forming anALD layer can comprise (i) introducing a first reactant gas from firstreactant gas source R1 into the enclosed volume 226, such that at leasta portion of the first reactant gas chemically bonds with the interiorsurface 229 to form a reactive layer. Controller 206 can be utilized tocontrol the formation of the reactant layer. Forming the ALD layer canfurther comprise (ii) removing unreacted first reactant gas and/orgaseous byproducts from the enclosed volume 226. Removing unreactedfirst reactant gas and/or gaseous byproducts from the enclosed volume226 can comprise pumping via pump 214 unreacted first reactant gasand/or gaseous byproducts out of enclosed volume 226 via second flowline 227 or first flow line 228 and optionally trap 212 via continuousflow of buffer (e.g., from a buffer source B) into enclosed volume 226.Controller 206 can be utilized to control the removal of unreacted firstreactant gas and/or gaseous byproducts from the enclosed volume 226,e.g., the timing of injection of one or more pulses of first reactantgas into a continuous flow of inert gas into the enclosed volume 226.Forming the ALD layer can further comprise (iii) introducing a secondreactant gas from a second reactant gas source R2 into the enclosedvolume 226, such that at least some of the second reactant gas bondswith the reactive layer to form an ALD layer. Controller 206 can beutilized to control the introducing of the second reactant gas from thesecond reactant gas source R2 into the enclosed volume 226. Forming theALD layer can further comprise (iv) removing unreacted second reactantgas and/or gaseous byproducts from the enclosed volume 226. As notedabove, steps (ii) and (iv) can be effected via pulsing of the firstreactant gas and the second reactant gas from first reactant gas sourceR1 and second reactant gas source R2 (which can, in aspects bepressurized cells of the reactant gas) into a continuous flow of inertgas into the enclosed volume 226, such that each pulse of reactant gasenters enclosed volume 226 subsequent introduction thereto ofcontinuously flowing inert gas. Steps (i) through (iv) of forming an ALDlayer can be repeated to obtain a desired number of ALD coatings and adesired thickness of each coating within the ALD layer. During one ormore of steps (i) through (iv) of forming the ALD layer, heating unit218A and/or preheater 218B can be operated to provide a desiredtemperature within enclosed volume 226. Controller 206 can be utilizedto control the temperature provided by heating unit 218A and/orpreheater 218B. One or both of the first reactant gas or the secondreactant gas can be provided from a source R1/R2 thereof via plasmagenerator 210. As noted hereinabove, utilizing plasma generator 210 toprovide one or both of the first reactant gas and/or the second reactantgas can enable surface coating to occur under a wider range of ambientconditions (e.g., temperatures and pressures) inside the enclosed volume226 as compared to a thermal approach using a heat source such asheating unit 218A, and/or enable a wider range of material properties tobe realized as compared to a thermal approach using a heat source suchas heating unit 218A.

In embodiments, the forming of the ALD layer or layers produced asdetailed hereinabove is performed prior to and/or subsequent todeposition of a CVD layer. That is, with reference now to FIG. 5 , anALD layer formed by repetition of a combination of one or more steps (i)through (iv) can be the base layer 404 and/or can be another layer 406deposited subsequent deposition of a disparate base layer (e.g., a layerin direct contact with interior surface 229) or subsequent deposition ofan underlying layer or “underlayer” (e.g., a layer deposited prior tothe ALD layer, but not in direct contact with interior surface 229). Inembodiments, ALD can be utilized to deposit an ALD coating inapplications in which no CVD coating is applied. Controller 206 can beutilized to precisely control the pulsing and timing (e.g., sequenceand/or residence time of each gas in enclosed volume 226) of gases ineach of the one or more steps (i) through (iv).

As noted hereinabove, the one or the plurality of first reactant gassources R1 can comprise one or a plurality of first pressurized cells,wherein the one or each of the plurality of first pressurized cellscomprises a first pressurized gas comprising the one or more firstreactant gases, wherein the first pressurized gas is at a pressure ofgreater than the pressure within the housing, apparatus, or tool202/well tool 202A (e.g., the interior/enclosed volume pressure),wherein the one or each of the plurality of first pressurized cells isfluidically coupled to one of the one or more first flow lines 228, andthe one or the plurality of second reactant gas sources can comprise oneor a plurality of second pressurized cells, wherein the one or each ofthe plurality of second pressurized cells comprises a second pressurizedgas comprising the one or more second reactant gases, wherein the secondpressurized gas is at a pressure of greater than the pressure within thehousing, apparatus, or tool 202/well tool 202A (e.g., theinterior/enclosed volume pressure), wherein the one or each of theplurality of second pressurized cells is fluidically coupled to one ofthe one or more second flow lines 227. In such aspects, the controller206 is in electronic communication with the one or the plurality offirst pressurized cells and the one or the plurality of secondpressurized cells, and is configured to control injection of one or morepulses of the first pressurized gas into a flow of inert gas in thefirst pressurized cell line and one or more pulses of the secondpressurized gas into a flow of inert gas in the second pressurized cellline, such that the one or more pulses of the first pressurized gas andthe one or more pulses of the second pressurized gas are separatelyintroduced into the enclosed volume with inert gas being introduced intothe enclosed volume 226 prior to and subsequent introduction thereto ofeach of the one or more pulses of the first pressurized gas and the oneor more pulses of the second pressurized gas. The first reactant gas andthe second reactant gas can thus be counter currently introduced intothe enclosed volume 226.

In embodiments the method can comprise or further comprise forming a CVDlayer by: (a) introducing at least a third reactant gas from a thirdreactant gas source R3 into the enclosed volume 226, such that the atleast the third reactant gas chemically reacts with the surface 229. Inembodiments, the method comprises both forming an ALD layer and a CVDlayer, wherein forming both an ALD layer and a CVD layer comprisesforming an ALD layer (e.g., an ALD base layer or underlayer) on thesurface 229 and subsequently forming the CVD layer on the ALD layer orforming the CVD layer (e.g., a CVD base layer or underlayer) on thesurface 229 and subsequently forming the ALD layer on the CVD layer.

For example and with reference now to FIG. 1A and FIG. 1B, forming a CVDlayer can comprise: (a) introducing at least one reactant gas into theenclosed volume 226 such that it chemically reacts with a surface (e.g.,interior surface 229) inside the enclosed volume 226. In some examples,forming the CVD layer can comprise introducing two or more reactantgases simultaneously and optionally continuously into the enclosedvolume 226 such that the two or more reactant gases chemically reactwith a surface (e.g., interior surface 229, optionally previously coatedwith an ALD layer and/or etched via ALE) inside the enclosed volume 226.Controller 206 can be utilized to control the formation of the CVDlayer. In embodiments, forming a CVD layer comprises introducing thirdreactant gas from a third gas source R3 and optionally a fourth reactantgas from a fourth gas source R4 into the enclosed volume 226 via a firstflow line 228 or a second flow line 227. Controller 206 can be utilizedto control the timing and duration of introduction of the third and/orfourth (or fifth, and so on) reactant gas into the enclosed volume 226during formation of the CVD layer. Forming the CVD layer can furthercomprise (b) removing unreacted third reactant gas and/or fourthreactant gas or so on reactant gases and/or gaseous byproducts from theenclosed volume 226. Steps (a) and (b) of forming a CVD layer can berepeated to obtain a desired number of CVD coatings and a desiredthickness of each coating within the CVD layer. Some combination of (a)and/or (b) may be utilized to form the CVD layer. Step (b) can beeffected by introducing of the third and/or fourth (or fifth, and so on)reactant gas into the enclosed volume 226 by injection thereof as one ormore pulses into a continuous flow of inert gas in the flow line intowhich the reactant gas is injected, in aspects.

During one or more of steps (a) or (b) of forming the CVD layer, heatingunit 218A or preheater 218B can be operated to provide a desiredtemperature within enclosed volume 226. Controller 206 can be utilizedto control the temperature provided by heating unit 218A and/orpreheater 218B. One or both of the third reactant gas or the fourthreactant gas (and optionally additional reactant gas(es)) can beprovided from a source R3/R4 thereof via plasma generator 210. As notedhereinabove, utilizing plasma generator 210 to provide one or both ofthe third reactant gas and/or the fourth reactant gas (and optionallyadditional reactant gas(es)) can enable surface coating to occur under awider range of ambient conditions (e.g., temperatures and pressures)inside the enclosed volume 226 as compared to a thermal approach using aheat source such as heating unit 218A and/or preheater 218B, and/orenable a wider range of material properties to be realized as comparedto a thermal approach using a heat source such as heating unit 218Aand/or preheater 218B.

In embodiments, the CVD layer or layers produced as detailed hereinaboveis performed prior to and/or subsequent to deposition of an ALD layer.That is, with reference now to FIG. 5 , a CVD layer formed by repetitionof a combination of one or more steps (a) and/or (b) can be the baselayer 404 and/or can be another layer 406 deposited subsequentdeposition of a disparate base layer (e.g., a layer in direct contactwith interior surface 229) or an underlying layer or underlayer (e.g., alayer deposited prior to deposition of this CVD layer, but not in directcontact with interior surface 229). In embodiments, CVD can be utilizedto deposit a CVD coating in applications in which no ALD coating isapplied. In such cases, gas sources R3/R4 can include third reactant gasand/or fourth reactant gas, or so on, but first reactant gas sources R1and/or second reactant gas sources R2 may be absent. (That is, therecitation of a third reactant gas from a third reactant gas source R3should not be interpreted to require the use of a first reactant gasfrom a first reactant gas source R1 and a second reactant gas from asecond reactant gas source R2.) Controller 206 can be utilized toprecisely control the pulsing and timing (e.g., the sequence andresidence time of each gas in enclosed volume 226) of gases in each ofthe one or more steps (a) and/or (b).

The method can comprise monitoring a thickness of the one or morecoating layers being deposited during the depositing 608, by measuring aconcentration of unreacted reactant gas (e.g., a concentration ofunreacted one or more first reactant gases and/or a concentration ofunreacted one or more second reactant gases) passing out of the enclosedvolume 226; measuring, via a quartz crystal microbalance, a mass beingdeposited during the depositing 608; or measuring, via an opticalmonitor, the thickness of the one or more coating layers being depositedat 608; and controlling a duration of the introducing of the reactant(s) (e.g., the introducing of the one or more first reactant gasesand/or the introducing of the one or more second reactant gases) intothe enclosed volume 226, an order of introducing of the reactant gases(e.g., the one or more first reactant gases and/or the one or moresecond reactant gases) into the enclosed volume 226, a concentration ofthe reactant gases (e.g., the one or more first reactant gases and/or ofthe one or more second reactant gases) being introduced into theenclosed volume 226, or a combination thereof to optimize the depositingof the one or more coating layers at 608. The monitoring of thethickness of the one or more coating layers can be effected via a sensorSA/SB.

As noted above, the method of coating the surface 229 of the interiorregion or volume 224 of the housing, apparatus, or tool 202/well tool202A can further comprise performing an atomic layer etching (ALE)process to pre-treat the enclosed volume 226 prior to the forming of theone or more coating layers on the all or the portion of the surface 229of the interior volume 224 of the housing, apparatus, or tool 202/welltool 202A and/or to reduce a thickness of at least one of the one ormore coating layers. ALE can comprise (1) applying an etching gas froman etching gas source EG to a surface in the enclosed volume 226, suchthat the surface chemically reacts with and adsorbs the etching gas; (2)purging the etching gas and any gaseous byproducts from the enclosedvolume 226; (3) applying low-energy ions to the portions of the surfacethat chemically reacted with the etching gas to etch away said portions;and (4) optionally purging byproducts from the enclosed volume 226.Applying the etching gas to the surface in the enclosed volume 226, cancomprise applying the etching gas to an uncoated surface 229 to enhancesubsequent deposition of a base layer comprising ALD or CVD or to asurface 229 upon which an ALD coating or a CVD coating was last applied(e.g., to an already coated surface 229). Applying the etching gas tothe surface can comprise actuating the fluid delivery system 208 tosupply the etching gas from etching gas source EG to within the enclosedvolume 226 via injecting the etching gas into a continuous flow of inertgas in a first flow line 228 or second flow line 227. Subsequent theapplying of the etching gas, performing the ALE can comprise (2) purgingthe etching gas and any gaseous byproducts from the enclosed volume 226,for example by actuating the pump 214 and/or actuating the fluiddelivery system 208 to continue flow of the inert gas (e.g., buffer gasfrom buffer source B) to within the enclosed volume 226. Performing theALE further comprises (3) applying low-energy ions to the portions ofthe surface that chemically reacted with the etching gas in steps (1)and/or (2) to etch away said portions. The low-energy ions can beprovided via ion generator 222. Performing the ALE can further compriseoptionally purging the enclosed volume 226, for example, via continuousflow of inert gas through housing or tool 202. The controller 206 beutilized to control the ALE. For example, the controller 206 canimplement (2) and/or (4) by actuating the pump 214, actuating the fluiddelivery system 208 to continually supply a buffer gas (e.g., buffer gasfrom buffer gas source B, which can be the same or different in (2) and(4)) to within the enclosed volume 226, or both. The controller 206 canimplement (3) by actuating an ion generator 222, which can supply thelow-energy ions to the enclosed volume 226. Some or all of these stepscan be repeated as many times as is required. Some combination of (1)through (4) may be utilized to perform the ALE. For example, not all of(1) to (4) need be utilized during the ALE (e.g., purging byproducts at(4) may be absent).

For example and with reference now to FIG. 1A and FIG. 1B, the method ofcoating the surface 229 of the interior region or volume 224 of thehousing, apparatus, or tool 202/well tool 202A can comprise: performingan atomic layer etching (ALE) process to pre-treat the enclosed volume226 prior to the forming of the one or more coating layers on the all orthe portion of the surface 229 of the interior volume 224 of thehousing, apparatus, or tool 202/well tool 202A and/or to reduce athickness of at least one of the one or more coating layers. That is,ALE etching can be performed on surface 229 prior to deposition of baselayer 404 thereupon, e.g., prior to deposition of a ALD or CVD baselayer on uncoated interior surface 229. Alternatively or additionally,performing ALE etching can be effected subsequent to deposition of a CVDlayer (e.g., subsequent to deposition of a CVD base layer 404 or anunderlying CVD layer 406), subsequent to deposition of an ALD layer(e.g., subsequent to deposition of an ALD base layer 404 or anunderlying ALD layer 406), or both subsequent to deposition of a CVDlayer and subsequent to deposition of an ALD layer (with the ALD layerbeing deposited before or after the CVD layer).

As described hereinabove, a method of coating a surface 229 of aninterior region or volume 224 of a housing, apparatus, or tool 202/welltool 202A according to this disclosure can further comprise flowing atopical reagent to at least one of the one or more coating layers,wherein the topical reagent is configured to react with the coatinglayer and thereby adjust a material characteristic of the coating layer.The flowing of the topical reagent TR to at least one of the one or morecoating layers can comprise flowing the topical reagent to a topmostcoating layer, wherein the topmost coating layer is a one of the one ormore coating layers farthest from the uncoated interior surface 229 ofthe enclosed interior volume 226 of the housing, apparatus, or tool202/well tool 202A. For example and with reference now to FIG. 1A andFIG. 1B, the flowing the topical reagent to at least one of the one ormore coating layers can comprise flowing the over a deposited ALD layer,flowing the topical reagent over a deposited CVD layer, flowing thetopical reagent into the enclosed volume 226 during formation of an ALDlayer (e.g., during one or more of the one or more steps (i) through(iv) of forming an ALD layer, as described hereinabove), flowing thetopical reagent into the enclosed volume 226 during formation of a CVDlayer (e.g., during one or more of the one or both steps (a) or (b) offorming a CVD layer, as described hereinabove), or a combinationthereof. The topical reagent can be introduced into the enclosed volumevia injection from topical reagent source TG into a continuous flow ofinert gas in a first flow line 228 or a second flow line 227.

As noted hereinabove, the housing, apparatus, or tool 202 can comprise afurnace tube, an aircraft component (e.g., a wing, a fuselage), acomponent of a water supply/treatment system; a component of a vehiclefuel system; a well tool 202A; or another housing, apparatus, or tool.

The method can further comprise placing a component within the interiorvolume 224 (e.g., within enclosed interior volume 226 which serves as adeposition chamber for the component placed therein) of the housing,apparatus, or tool 202/well tool 202A and concurrently coating a surfaceof the component and interior surface 229 of the housing, apparatus, ortool 202/well tool 202A.

Forming the one or more coating layers on all or a portion of thesurface 229 of the enclosed interior volume 226 of the housing,apparatus, or tool 202/well tool 202A via reaction of the reactantgases, optionally in the presence of the plasma, can further compriseactuating the housing, apparatus, or tool 202/well tool 202A to exposean additional surface (e.g., one or more surfaces of a telescopingcomponent of the tool 202/well tool 202A) in the enclosed interiorvolume 226 of the housing, apparatus, or tool 202/well tool 202A andcoating at least a portion of the additional surface, as describedhereinabove.

The forming of the one or more coating layers can be effected at aworksite (e.g., wellsite 100) at which the housing, apparatus, or tool202/well tool 202A will subsequently be employed (e.g., well tool 202Aplaced downhole for use), has previously been employed (e.g., well tool202A recovered from downhole use), or both. For example, one or morecoating layers can be formed on a well tool 202A at a wellsite 100 atwhich the well tool 202A has been and/or will be employed.

The housing, apparatus, or tool 202 can comprise a well tool 202A. Thewell tool 202A can comprise a logging while drilling (LWD) tool, ameasurements while drilling (MWD) tool, or a sampling while drilling(SWD) tool. In such embodiments, the interior volume 224 of the welltool 202A can comprise a fluid flow path configured for flow of aformation fluid from an exterior E of the well tool 202A through aninterior (e.g., interior volume 224) of the well tool 202A. In someembodiments, the interior volume 224 of the well tool 202A can comprisea fluid flow path configured for flow of a formation fluid from anexterior E of the well tool 202A through an inlet(s) (205A/B) and aninterior (e.g., interior volume 224) of the well tool 202A and back outof the well tool 202A via discard line outlet 207A. In some embodiments,the interior volume 224 of the well tool 202A can comprise a fluid flowpath configured for flow of a formation fluid from an exterior E of thewell tool 202A through an inlet (e.g., sample line inlet 205B) andinterior (e.g., interior volume 224) of the well tool 202A and into asample chamber 90.

The method can further comprise, subsequent the coating, placing thehousing, apparatus, or tool 202/well tool 202A in an operatingenvironment therefor (e.g., a wellbore 102) and contacting the coatedsurface 229 with an operations fluid (e.g., contacting the coatedsurface 229 with formation fluid from the formation 104). For exampleand with reference now to FIG. 7 , due to the portability of the hereindisclosed coating system 200/well tool coating system 200A, a coatingcan be formed on all or a portion of the interior surface 229 of theenclosed volume 226 of the well tool 202A, and the well tool 202Asubsequently introduced into a wellbore 102 for utilization thereof(e.g., for taking one or more formation fluid samples). Prior to coatingthe tool 202A, analysis of the formation fluid and/or an anticipatedcomposition thereof can be utilized to determine what coating to depositon one or more surfaces of an interior volume 224 of the well tool 202A.Subsequent utilization downhole in wellbore 102 (for example subsequentthe taking of formation samples in sample chambers 90 as describedhereinabove with reference to the well tool 202A of FIG. 7 ), formationsample analysis can again be utilized to determine whether or not thewell tool 202A should be subjected to further coatings with well toolcoating system 200A. For example, in applications where anticipatedformation composition is utilized to determine an initial coating of theenclosed volume(s) 226 of well tool 202A, following utilization of welltool 202A downhole to obtain the one or more formation fluid samples inthe one or more sample chambers 90, analysis of the formation samplesretrieved from downhole by the well tool 202A can be utilized todetermine if alternative and/or additional coating layers should bedeposited within well tool 202A. For example, should anticipatedformation composition not include significant mercury (Hg) and/orhydrogen sulfide (H₂S), and no initial coating be performed within welltool 202A, while analysis of sample(s) retrieved from the formation 104indicates the presence of substantial H₂S and/or Hg (or anothercomponent which can interfere with formation fluid analysis and/orcorrode well tool 202A), a coating process of the type disclosed hereincan be performed on-site to reduce the interaction of the interiorsurface 229 with the formation fluid during subsequent testing with welltool 202A. Alternatively, if an initial coating selected for the welltool 202A were to prove ineffective to prevent and/or reduce interactionof the analyzed formation fluid obtained with well tool 202A, a new oradditional coating of well tool 202A can be performed based on theanalysis of the obtained formation fluid in sample chamber(s) 90 priorto further sampling therewith. If desired, etching to remove all or aportion of prior deposited coating(s) can be effected via ALE, asdetailed hereinabove, prior to deposition of the new or additionalcoating layer(s).

Those of ordinary skill in the art will readily appreciate variousbenefits that may be realized by the present disclosure. The hereindisclosed coating system 200/well tool coating system 200A enableon-site coating of interior surfaces 229 of a housing, apparatus, ortool 202/well tool 202A at a jobsite, for example, at a wellsite 100where a downhole tool 202A will be and/or has previously been utilized.This allows for the deposition of coatings within tools upondetermination of a composition of a fluid to which the interior of thehousing, apparatus, or tool 202/well tool 202A will subsequently beemployed. The coatings can thus be tailored to meet the needs of aparticular application at hand and thereby avoid costly delaysassociated with transporting a housing, apparatus, or tool 202/well tool202A to a traditional coating facility at a fixed location that may behundreds of miles from the worksite.

Counter current introduction of reactant gas, as described herein, canprovide for more uniform coating of the interior surface 229. Forexample, by offering counter-injection wherein the pulse is the samereactant species, reactant can be adequately delivered to the entiresurface of the tool being coated, regardless of length. Utilizingpressurized cell(s) to provide pulses of reactant gas can allow for moreuniform coating of the interior surface 229, and/or coating atsubstantially atmospheric pressure within housing, apparatus, or tool202, in aspects. Utilization of the pressurized cell(s) can enable theuse of a reactant having a lower vapor pressure than the currentpressure of the tool being coated. For example, even if the vaporpressure of one of the reactants, (e.g., trimethylaluminum) has a vaporpressure (e.g., 0.01 atm) substantially below that of the enclosedvolume within the housing, apparatus, or tool 202/well tool 202A (e.g.,atmospheric pressure) it can be introduced via the pressurized cellwithout the use of a mechanical pump to pull a vacuum on the tool bodyand decrease the pressure thereof below the vapor pressure of thereactant.

In accordance with the present disclosure, it may be desirable todeposit a coating on a surface (e.g., within a well tool) to withstand aparticular environment to which the surface will be exposed duringoperation, and thereby prolong a life of a housing, apparatus or toolcomprising the surface. In contrast to traditional deposition systemsthat require a well tool to be disassembled into subcomponents of smallenough size to fit inside an expensive commercial vacuum-chamber, whichserves as a deposition chamber, housings, apparatus, and tools (e.g.,well tools) need not be disassembled prior to coating with the methods,systems, and devices disclosed herein. Furthermore, in contrast totransporting a housing, apparatus, or tool to a commercialvacuum-chambers located at manufacturing facilities or laboratoryfacilities (which restricts when and how many times a surface coatingprocess can be applied to the well tool), in accordance with the presentdisclosure housing, apparatus, and tools (e.g., well tools) can becoated proximate a jobsite (e.g., wellsite) and need not be transported,thereby saving the cost and time associated with transportation andpromotes the application of multiple coatings (e.g., between jobs) asneeded.

The foregoing description of certain examples, including illustratedexamples, has been presented only for the purpose of illustration anddescription and is not intended to be exhaustive or to limit thedisclosure to the precise forms disclosed. Numerous modifications,adaptations, and uses thereof will be apparent to those skilled in theart without departing from the scope of the disclosure. For instance,any example(s) described herein can be combined with any otherexample(s) to yield further examples.

ADDITIONAL DISCLOSURE

The following are non-limiting, specific embodiments in accordance withthe present disclosure:

In a first embodiment, a coating system for coating, with one or moresurface coating processes, an interior surface of a housing defining aninterior volume, comprises: a first closure and a second closure tosealingly engage with a first end and a second end, respectively, of thehousing to provide an enclosed volume; a first flow line fluidicallycoupled to the first closure and a second flow line fluidically coupledto the second closure, wherein the first flow line, the second flowline, or both are fluidically connected to an inert gas source; one or aplurality of reactant gas sources, wherein the one or each of theplurality of reactant gas sources comprises a reactant gas and isfluidically coupled to the first flow line, the second flow line orboth; and a controller in electronic communication with the one or theplurality of reactant gas sources and the inert gas source, wherein thecontroller is configured to control flow of the inert gas from the inertgas source into the enclosed volume, and to control counter currentinjection of the reactant gas from the one or the plurality of reactantgas sources into the enclosed volume such that introduction of one ormore pulses of the reactant gas into the enclosed volume are separatedby introduction of the inert gas into the enclosed volume, and one ormore coating layers are deposited on all or a portion of the interiorsurface within the enclosed volume.

A second embodiment can include the coating system of the firstembodiment comprising the plurality of reactant gas sources, one or morefirst flow lines, and one or more second flow lines, wherein theplurality of reactant gas sources include one or a plurality of firstreactant gas sources comprising one or more first reactant gases and oneor a plurality of second reactant gas sources comprising one or moresecond reactant gases, wherein the one or each of the plurality of thefirst reactant gas sources is fluidically coupled to one of the one ormore first flow lines and wherein the one or each of the plurality ofthe second reactant gas sources is fluidically coupled to one of the oneor more second flow lines.

A third embodiment can include the coating system of the secondembodiment, wherein the one or the plurality of first reactant gassources comprise one or a plurality of first pressurized cellscomprising a first pressurized gas, wherein the first pressurized gascomprises the one or more first reactant gases, wherein the firstpressurized gas is at a pressure of greater than a pressure within theenclosed volume, wherein the one or each of the plurality of firstpressurized cells is fluidically coupled to a first pressurized cellline comprising one of the one or more first flow lines, wherein the oneor the plurality of second reactant gas sources comprise one or aplurality of second pressurized cells comprising a second pressurizedgas, wherein the second pressurized gas comprises the one or more secondreactant gases, wherein the second pressurized gas is at a pressure ofgreater than the pressure within the enclosed volume, wherein the one oreach of the plurality of second pressurized cells is fluidically coupledto a second pressurized cell line comprising one of the one or moresecond flow lines.

A fourth embodiment can include the coating system of the thirdembodiment, wherein the controller is in electronic communication withthe one or the plurality of first pressurized cells and the one or theplurality of second pressurized cells, and wherein the controller isconfigured to control injection of one or more pulses of the firstpressurized gas into a flow of inert gas in the first pressurized cellline and one or more pulses of the second pressurized gas into a flow ofinert gas in the second pressurized cell line, such that the one or morepulses of the first pressurized gas and the one or more pulses of thesecond pressurized gas are separately introduced into the enclosedvolume with inert gas being introduced into the enclosed volume prior toand subsequent introduction thereto of each of the one or more pulses ofthe first pressurized gas and the one or more pulses of the secondpressurized gas.

A fifth embodiment can include the coating system of the thirdembodiment or fourth embodiment, comprising the plurality of firstpressurized cells, the plurality of second pressurized cells, or boththe plurality of first pressurized cells and the plurality of secondpressurized cells.

A sixth embodiment can include the coating system of the fifthembodiment, wherein the controller is configured to alternateintroduction of one or more pulses of the first pressurized gas with oneor more pulses of the second pressurized gas.

A seventh embodiment can include the coating system of the sixthembodiment, wherein the one or more first reactant gases and the one ormore second reactant gases are the same or different.

An eighth embodiment can include the coating system of the seventhembodiment, wherein the one or more first reactant gases comprisetrimethyl-aluminum, wherein the one or more second reactant gasescomprise ozone or water, and wherein the one or more coating layerscomprise aluminum oxide.

A ninth embodiment can include the coating system of any one of thesecond to eighth embodiments, wherein the first pressurized gas consistsof the one or more first reactant gases, or wherein the firstpressurized gas further comprises from about 10 to about 90 volumepercent (vol %), from about 20 to about 80 vol %, or from about 30 toabout 70 vol % of a buffer gas; and/or wherein the second pressurizedgas consists of the one or more second reactant gases, or wherein thesecond pressurized gas further comprises from about 10 to about 90volume percent (vol %), from about 20 to about 90 vol %, or from about30 to about 70 vol % of a buffer gas.

A tenth embodiment can include the coating system of any one of thefirst to ninth embodiments further comprising: a plasma sourcefluidically coupled to the housing to provide plasma for the one or moresurface coating processes; an ion source fluidically coupled to thehousing to provide ions for the one or more surface coating processes; aheating unit in thermal communication with the housing to heat thehousing for the one or more surface coating processes; or anycombination thereof, wherein the controller is further in electroniccommunication with the plasma source, the ion source, the heating unit,or the combination thereof to control the plasma source, the ion source,the heating unit, or the combination thereof during the one or moresurface coating processes.

An eleventh embodiment can include the coating system of any one of thefirst to tenth embodiments, further comprising: a heater; and a dryinggas source, wherein the heater is in thermal communication with thedrying gas source, the housing, and/or a line fluidically coupling thedrying gas source and the housing such that a hot drying gas can beprovided within the enclosed volume to dry the interior surface of thehousing prior to introduction of any of the one or more first reactantgases or the one or more second reactant gases thereto.

A twelfth embodiment can include the coating system of the eleventhembodiment, wherein the controller is in further electroniccommunication with the heater and/or the drying gas source to controlthe heater, and/or the drying gas source during the one or more surfacecoating processes.

A thirteenth embodiment can include the coating system of the twelfthembodiment further comprising one or more pumps upstream or downstreamof the housing, wherein the one or more pumps include a vacuum pump onat least one of the one or more first flow lines, a vacuum pump on atleast one of the one or more second flow lines, or both a vacuum pump onat least one of the one or more first flow lines and a vacuum pump on atleast one of the one or more second flow lines, wherein the vacuum pumpis configured to create a vacuum in the enclosed volume during drying,whereby the one or more first flow lines or the one or more second flowlines having the vacuum pump can operate as a vacuum line.

A fourteenth embodiment can include the coating system of the thirteenthembodiment further comprising a moisture detector on the vacuum line,wherein the moisture detector is operable to measure a moisture contentof the hot drying gas removed from the enclosed volume during thedrying.

A fifteenth embodiment can include the coating system of any one of thefirst to fourteenth embodiments, wherein the coating system is operablefor coating the interior surface at a coating temperature of roomtemperature, a coating pressure of atmospheric pressure, or both acoating temperature of room temperature and a coating pressure ofatmospheric pressure.

A sixteenth embodiment can include the coating system of any one of thefirst to fifteenth embodiments, wherein the one or more surface coatingprocesses comprise chemical vapor deposition (CVD), atomic layerdeposition (ALD), or both.

A seventeenth embodiment can include the coating system of any one ofthe first to sixteenth embodiments further comprising a sensor formonitoring a thickness of the one or more coating layers, wherein thesensor comprises a sensor for measuring a concentration of uneactedreactants passing out of the enclosed volume, a quartz crystalmicrobalance, or an optical monitor, wherein the controller is furtherin electronic communication with the sensor and operable to adjust aduration of introduction of the one or more first reactant gases and/orthe one or more second reactant gases, an order of introduction of theone or more first reactant gases and/or the one or more second reactantgases, a concentration of the one or more first reactant gasesintroduced into the enclosed volume and/or of the one or more secondreactant gases introduced into the enclosed volume, or a combinationthereof.

An eighteenth embodiment can include the coating system of any one ofthe first to seventeenth embodiments, wherein the interior volume has anaspect ratio that is less than or equal to about 0.5, wherein the aspectratio is an average width of the interior volume divided by an averagelength thereof.

A nineteenth embodiment can include the coating system of any one of thefirst to eighteenth embodiments, wherein the housing comprises a furnacetube, an aircraft component, a component of a water supply/treatmentsystem, a component of a vehicle fuel system, or a well tool.

A twentieth embodiment can include the coating system of the nineteenthembodiment, wherein the component comprises the well tool, wherein thewell tool is a logging while drilling (LWD) tool, a measurements whiledrilling (MWD) tool, or a sampling while drilling (SWD) tool, andwherein a volume of the well tool defines a fluid flow path for flow ofa formation fluid from an exterior of the well tool through an interiorof the well tool.

A twenty first embodiment can include the coating system of any one ofthe first to twentieth embodiments, wherein the coating system isportable and further comprises a hauler to transport the coating systemto a worksite proximate the housing.

A twenty second embodiment can include the coating system of any one ofthe first to twenty first embodiments comprising a plurality of housingsconnected in series and/or in parallel, wherein each of the plurality ofhousings comprise a first closure and a second closure to sealinglyengage with a first end and a second end, respectively, of the housingto provide an enclosed volume, and one or more first flow linesfluidically coupled to the first closure and one or more second flowlines fluidically coupled to the second closure; wherein the second flowlines fluidically coupled to each of the plurality of housings arefluidically coupled as the first flow lines to any immediatelydownstream housing.

A twenty third embodiment can include the coating system of the twentysecond embodiment, wherein the plurality of housings are connected inseries, wherein each of the plurality of housings except a last housingof the series of housings is fluidically coupled with an immediatelydownstream housing via a U-shaped connector.

A twenty fourth embodiment can include the coating system of the twentythird embodiment, wherein one or more of the U shaped connectors arefluidically coupled with one of the plurality of first reactant gassources and/or one of the plurality of second reactant gas sources,whereby the one or more first reactant gases and/or the one or moresecond reactant gases can be injected into the one or more U-shapedconnectors and thereby introduced into the interior volume of a housingimmediately downstream of the one or more U-shaped connectors.

A twenty fifth embodiment can include the coating system of the twentythird or twenty fourth embodiment, wherein each of the plurality ofhousings comprises a cylinder, and wherein the plurality comprises fromabout 2 to about 30, from about 2 to about 15, or from about 5 to about10 housings.

A twenty sixth embodiment can include the coating system of the twentyfifth embodiment, wherein each of the cylinders has a length in a rangeof from about from about 1 to about 10 feet, from about 2 to about 9feet, of from about 3 to about 8 feet, and an inside diameter in a rangeof from about ¼ inch to about 10 inches, from about ¼ inch to about 12inch, or from about 1 cinch to about 15 inches.

In a twenty seventh embodiment, a method of coating, with one or moresurface coating processes, an interior surface of a housing defining aninterior volume, comprises: positioning a coating system and a housingproximate each other, wherein the coating system comprises: a first flowline fluidically coupled to the first closure and a second flow linefluidically coupled to the second closure, wherein the first flow line,the second flow line, or both are fluidically connected to an inert gassource; one or a plurality of reactant gas sources, wherein the one oreach of the plurality of reactant gas sources comprises a reactant gasand is fluidically coupled to the first flow line, the second flow lineor both; and a controller in electronic communication with the one orthe plurality of reactant gas sources and the inert gas source, whereinthe controller is configured to control flow of the inert gas from theinert gas source into the enclosed volume, and to control countercurrent injection of the reactant gas from the one or the plurality ofreactant gas sources into the enclosed volume such that introduction ofone or more pulses of the reactant gas into the enclosed volume areseparated by introduction of the inert gas into the enclosed volume, andone or more coating layers are deposited on all or a portion of theinterior surface within the enclosed volume, sealingly engaging thefirst closure to a first end of the housing and sealingly engaging thesecond closure to outlet second end of the housing to form the enclosedvolume; counter currently injecting the reactant gas from the one or theplurality of reactant gas sources into the enclosed volume such thatintroduction of one or more pulses of the reactant gas into the enclosedvolume are separated by introduction of the inert gas into the enclosedvolume; and depositing the one or more coating layers on all or aportion of the interior surface within the enclosed volume.

A twenty eighth embodiment can include the method of the twenty seventhembodiment comprising the plurality of reactant gas sources, one or morefirst flow lines, and one or more second flow lines, wherein theplurality of reactant gas sources include one or a plurality of firstreactant gas sources comprising one or more first reactant gases and oneor a plurality of second reactant gas sources comprising one or moresecond reactant gases, wherein the one or each of the plurality of thefirst reactant gas sources is fluidically coupled to one of the one ormore first flow lines and wherein the one or each of the plurality ofthe second reactant gas sources is fluidically coupled to one of the oneor more second flow lines.

A twenty ninth embodiment can include the method of the twenty eighthembodiment, wherein the one or the plurality of first reactant gassources comprise one or a plurality of first pressurized cells, whereinthe one or each of the plurality of first pressurized cells comprises afirst pressurized gas comprising the one or more first reactant gases,wherein the first pressurized gas is at a pressure of greater than thepressure within the enclosed volume, wherein the one or each of theplurality of first pressurized cells is fluidically coupled to one ofthe one or more first flow lines, wherein the one or the plurality ofsecond reactant gas sources comprise one or a plurality of secondpressurized cells, wherein the one or each of the plurality of secondpressurized cells comprises a second pressurized gas comprising the oneor more second reactant gases, wherein the second pressurized gas is ata pressure of greater than the pressure within the enclosed volume,wherein the one or each of the plurality of second pressurized cells isfluidically coupled to one of the one or more second flow lines.

A thirtieth embodiment can include the method of the twenty ninthembodiment, wherein the controller is in electronic communication withthe one or the plurality of first pressurized cells and the one or theplurality of second pressurized cells, and wherein the controller isconfigured to control injection of one or more pulses of the firstpressurized gas into a flow of inert gas in the first pressurized cellline and one or more pulses of the second pressurized gas into a flow ofinert gas in the second pressurized cell line, such that the one or morepulses of the first pressurized gas and the one or more pulses of thesecond pressurized gas are separately introduced into the enclosedvolume with inert gas being introduced into the enclosed volume prior toand subsequent introduction thereto of each of the one or more pulses ofthe first pressurized gas and the one or more pulses of the secondpressurized gas.

A thirty first embodiment can include the method of the twenty ninthembodiment or the thirtieth embodiment further comprising forming theone or each of the plurality of first pressurized cells and/or the oneor each of the second pressurized cells by reducing a pressure of a cellto less than a vapor pressure of the one or more first reactant gasesand/or the one or more second reactant gases, respectively, introducingthe one or more first reactant gases and/or the one or more secondreactant gases, respectively, into the cell, and increasing the pressureof the cell to the pressure of greater than the pressure within theenclosed volume via introduction of additional gas into the cell,wherein the additional gas comprises at least one of the one or morefirst reactant gases and/or at least one of the one or more secondreactant gases, respectively, or an inert buffer gas.

A thirty second embodiment can include the method of any one of thetwenty ninth to thirty first embodiments comprising the plurality offirst pressurized cells, the plurality of second pressurized cells, orboth the plurality of first pressurized cells and the plurality ofsecond pressurized cells.

A thirty third embodiment can include the method of any one of thetwenty eighth to thirty second embodiments, comprising alternatingintroduction of one or more pulses of the first pressurized gas into theenclosed volume with introduction of one or more pulses of the secondpressurized gas into the enclosed volume.

A thirty fourth embodiment can include the method of the thirty thirdembodiment, wherein the one or more first reactant gases and the one ormore second reactant gases are the same or different.

A thirty fifth embodiment can include the method of the thirty fourthembodiment, wherein the one or more first reactant gases and the one ormore second reactant gases are the same, whereby one or more pulses ofthe same one or more reactant gases are alternately introduced into theenclosed volume counter currently via the first end and the second endof the housing.

A thirty sixth embodiment can include the method of any one of thetwenty seventh to thirty fifth embodiments, wherein the one or morefirst reactant gases comprise trimethyl-aluminum, wherein the one ormore second reactant gases comprise ozone or water, and wherein the oneor more coating layers comprise aluminum oxide.

A thirty seventh embodiment can include the method of any one of thetwenty seventh to thirty sixth embodiments, wherein the one or morecoating layers comprise an ALD layer, a CVD layer, or both.

A thirty eighth embodiment can include the method of any one of thetwenty seventh to thirty seventh embodiments further comprising dryingthe interior surface of the housing prior to introducing any of the oneor more first reactant gases or the one or more second reactant gasesinto the housing.

A thirty ninth embodiment can include the method of the thirty eighthembodiment, wherein drying comprises heating under vacuum.

A fortieth embodiment can include the method of the thirty eighthembodiment or thirty ninth embodiment, wherein drying comprisesproviding a hot drying gas in the enclosed volume, and monitoring thedrying by measuring a moisture content of the hot drying gas passing outof the housing during the drying.

A forty first embodiment can include the method of any one of the firstto fortieth embodiments further comprising drying to a moisture contentof less than or equal to about 0.01, 0.005, or 0.001 volume percent (vol%) moisture.

A forty second embodiment can include the method of any one of thetwenty seventh to forty first embodiments further comprising: monitoringa thickness of the one or more coating layers being deposited during thedepositing, by measuring a concentration of unreacted one or more firstreactant gases and/or a concentration of unreacted one or more secondreactant gases passing out of the enclosed volume; measuring, via aquartz crystal microbalance, a mass being deposited during thedepositing; or measuring, via an optical monitor, the thickness of theone or more coating layers being deposited; and controlling a durationof the introducing of the one or more first reactant gases and/or theintroducing of the one or more second reactant gases into the enclosedvolume, an order of introducing of the one or more first reactant gasesand/or the one or more second reactant gases into the enclosed volume, aconcentration of the one or more first reactant gases and/or of the oneor more second reactant gases being introduced into the enclosed volume,or a combination thereof to optimize the depositing of the one or morecoating layers.

A forty third embodiment can include the method of any one of the twentyseventh to forty second embodiments, wherein the one or more surfacecoating processes comprise one or more chemical vapor deposition (CVD),one or more atomic layer deposition (ALD), or both.

A forty fourth embodiment can include the method of any one of thetwenty seventh to forty third embodiments, further comprising: (i)forming an ALD layer by: introducing a pulse of a first pressurized gascomprising the one or more first reactant gases into the enclosed volumevia a first pressurized cell, such that at least a portion of the firstpressurized gas chemically bonds with the interior surface to form areactive layer; removing unreacted first reactant gas and/or gaseousbyproducts from the enclosed volume via passage of inert gas introducedsubsequent the pulse of the first pressurized gas; and introducing apulse comprising a second pressurized gas comprising the one or moresecond reactant gases into the enclosed volume, such that at least someof the second pressurized gas bonds with the reactive layer to form theALD layer; (ii) forming a CVD layer by: introducing a pulse comprising athird pressurized gas comprising at least a third reactant gas into theenclosed volume via a third pressurized cell such that the at least thethird pressurized gas chemically reacts with the interior surface toform the CVD layer; or (iii) both forming an ALD layer via (i) and a CVDlayer via (ii), wherein forming both an ALD layer and a CVD layercomprises forming an ALD layer on the interior surface and subsequentlyforming the CVD layer on the ALD layer or forming the CVD layer on theinterior surface and subsequently forming the ALD layer on the CVDlayer.

A forty fifth embodiment can include the method of the forty fourthembodiment further comprising performing an atomic layer etching (ALE)process to pre-treat the interior surface prior to the forming of theone or more coating layers and/or to reduce a thickness of at least oneof the one or more coating layers.

A forty sixth embodiment can include the method of the forty fifthembodiment, wherein ALE comprises: introducing an etching gas to theenclosed volume such that the interior surface chemically reacts withand adsorbs the etching gas; purging the etching gas and any gaseousbyproducts from the enclosed volume; and applying low-energy ions to theportions of the surface that chemically reacted with the etching gas toetch away said portions.

A forty seventh embodiment can include the method of any one of theforty fifth to forty sixth embodiments further comprising introducing atopical reagent to at least one of the one or more coating layers,wherein the topical reagent reacts with the at least one coating layerto adjust a material characteristic of the at least one coating layer.

A forty eighth embodiment can include the method of any one of the fortythird to forty seventh embodiments, wherein the introducing the topicalreagent to at least one of the one or more coating layers comprisesintroducing the topical reagent to a topmost coating layer, the topmostcoating layer being one of the one or more coating layers positionedfarthest away from the interior surface.

A forty ninth embodiment can include the method of any one of the twentyseventh to forty eighth embodiments, wherein the housing comprises afurnace tube, an aircraft component, a component of a watersupply/treatment system, or a component of a vehicle fuel system.

A fiftieth embodiment can include the method of any one of the twentyseventh to forty ninth embodiments, wherein the housing comprises a welltool, wherein the well tool is a logging while drilling (LWD) tool, ameasurements while drilling (MWD) tool, or a sampling while drilling(SWD) tool, and wherein a volume of the well tool defines a fluid flowpath for flow of a formation fluid from an exterior of the well toolthrough an interior of the well tool.

A fifty first embodiment can include the method of the fiftiethembodiment, wherein forming the one or more coating layers on all or theportion of the interior surface further comprises actuating the welltool to expose an additional interior surface of the well tool andcoating at least a portion of the additional interior surface.

A fifty second embodiment can include the method of the fifty firstembodiment further comprising placing the well tool in a wellbore andcontacting the formation fluid with the coated surface.

A fifty third embodiment can include the method of the fifty secondembodiment, wherein the well tool is a formation sampling tool, andfurther comprising taking a formation fluid sample with the well tool,retrieving the formation fluid sample from the wellbore, performing acomposition analysis of the formation fluid sample, and determiningwhether or not to recoat all or a portion of the interior surface of thewell tool based on the compositional analysis.

In a fifty fourth embodiment, a method of coating an interior surface ofa housing defining a volume, comprises: enclosing all or a portion ofthe volume of the housing to yield an enclosed volume; introducing oneor more reactant gases to the enclosed volume via a plurality of inlets;and forming one or more coating layers on all or a portion of aninterior surface of the housing via atomic layer deposition (ALD) orchemical vapor deposition (CVD) of the one or more reactant gases,wherein a first reactant gas of the one or more reactant gases isintroduced into the enclosed volume counter currently from introductionof a second reactant gas of the one or more reactant gases into theenclosed volume.

A fifty fifth embodiment can include the method of the fifty fourthembodiment further comprising introducing the first reactant gas as apulse of the first reactant gas from one or more first pressurizedcells, wherein each of the one or more first pressurized cells comprisesa first pressurized gas comprising the first reactant gas, wherein thefirst pressurized gas is at a pressure of greater than the pressurewithin the enclosed volume, and wherein each of the one or more firstpressurized cells is fluidically coupled to an inlet on a first end ofthe housing; introducing the second reactant gas as a pulse of thesecond reactant gas from one or more second pressurized cells, whereineach of the one or more second pressurized cells comprises a secondpressurized gas comprising the second reactant gas, wherein the secondpressurized gas is at a pressure of greater than the pressure within theenclosed volume, and wherein each of the one or more second pressurizedcells is fluidically coupled to an inlet on a second end of the housing.

A fifty sixth embodiment can include the method of any one of the fiftyfourth to fifty fifth embodiments, wherein the first reactant gas andthe second reactant gas are the same or different.

While embodiments have been shown and described, modifications thereofcan be made by one skilled in the art without departing from the spiritand teachings of this disclosure. The embodiments described herein areexemplary only, and are not intended to be limiting. Many variations andmodifications of the embodiments disclosed herein are possible and arewithin the scope of this disclosure. Where numerical ranges orlimitations are expressly stated, such express ranges or limitationsshould be understood to include iterative ranges or limitations of likemagnitude falling within the expressly stated ranges or limitations(e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a numericalrange with a lower limit, R1, and an upper limit, Ru, is disclosed, anynumber falling within the range is specifically disclosed. Inparticular, the following numbers within the range are specificallydisclosed: R=Rl+k*(Ru−Rl), wherein k is a variable ranging from 1percent to 100 percent with a 1 percent increment, i.e., k is 1 percent,2 percent, 3 percent, 4 percent, 5 percent, . . . 50 percent, 51percent, 52 percent, . . . , 95 percent, 96 percent, 97 percent, 98percent, 99 percent, or 100 percent. Moreover, any numerical rangedefined by two R numbers as defined in the above is also specificallydisclosed. Use of the term “optionally” with respect to any element of aclaim is intended to mean that the subject element is required, oralternatively, is not required. Both alternatives are intended to bewithin the scope of the claim. Use of broader terms such as comprises,includes, having, etc. should be understood to provide support fornarrower terms such as consisting of, consisting essentially of,comprised substantially of, etc.

Accordingly, the scope of protection is not limited by the descriptionset out above but is only limited by the claims which follow, that scopeincluding all equivalents of the subject matter of the claims. Each andevery claim is incorporated into the specification as an embodiment ofthe present disclosure. Thus, the claims are a further description andare an addition to the embodiments of the present disclosure. Thediscussion of a reference herein is not an admission that it is priorart, especially any reference that may have a publication date after thepriority date of this application. The disclosures of all patents,patent applications, and publications cited herein are herebyincorporated by reference, to the extent that they provide exemplary,procedural, or other details supplementary to those set forth herein.

What is claimed is:
 1. A coating system for coating, with one or moresurface coating processes, an interior surface of a housing defining aninterior volume, the coating system comprising: a first closure and asecond closure to sealingly engage with a first end and a second end,respectively, of the housing to provide an enclosed volume; a first flowline fluidically coupled to the first closure and a second flow linefluidically coupled to the second closure, wherein the first flow line,the second flow line, or both are fluidically connected to an inert gassource; one or a plurality of reactant gas sources, wherein the one oreach of the plurality of reactant gas sources comprises a reactant gasand is fluidically coupled to the first flow line, the second flow lineor both; and a controller in electronic communication with the one orthe plurality of reactant gas sources and the inert gas source, whereinthe controller is configured to control flow of the inert gas from theinert gas source into the enclosed volume, and to control countercurrent injection of the reactant gas from the one or the plurality ofreactant gas sources into the enclosed volume such that introduction ofone or more pulses of the reactant gas into the enclosed volume areseparated by introduction of the inert gas into the enclosed volume, andone or more coating layers are deposited on all or a portion of theinterior surface within the enclosed volume.
 2. The coating system ofclaim 1, comprising the plurality of reactant gas sources, one or morefirst flow lines, and one or more second flow lines, wherein theplurality of reactant gas sources include one or a plurality of firstreactant gas sources comprising one or more first reactant gases and oneor a plurality of second reactant gas sources comprising one or moresecond reactant gases, wherein the one or each of the plurality of thefirst reactant gas sources is fluidically coupled to one of the one ormore first flow lines and wherein the one or each of the plurality ofthe second reactant gas sources is fluidically coupled to one of the oneor more second flow lines, wherein the one or more first reactant gasesand the one or more second reactant gases are the same or different. 3.The coating system of claim 2, wherein the one or the plurality of firstreactant gas sources comprise one or a plurality of first pressurizedcells comprising a first pressurized gas, wherein the first pressurizedgas comprises the one or more first reactant gases, wherein the firstpressurized gas is at a pressure of greater than a pressure within theenclosed volume, wherein the one or each of the plurality of firstpressurized cells is fluidically coupled to a first pressurized cellline comprising one of the one or more first flow lines, wherein the oneor the plurality of second reactant gas sources comprise one or aplurality of second pressurized cells comprising a second pressurizedgas, wherein the second pressurized gas comprises the one or more secondreactant gases, wherein the second pressurized gas is at a pressure ofgreater than the pressure within the enclosed volume, wherein the one oreach of the plurality of second pressurized cells is fluidically coupledto a second pressurized cell line comprising one of the one or moresecond flow lines.
 4. The coating system of claim 3, wherein thecontroller is in electronic communication with the one or the pluralityof first pressurized cells and the one or the plurality of secondpressurized cells, and wherein the controller is configured to controlinjection of one or more pulses of the first pressurized gas into a flowof inert gas in the first pressurized cell line and one or more pulsesof the second pressurized gas into a flow of inert gas in the secondpressurized cell line, such that the one or more pulses of the firstpressurized gas and the one or more pulses of the second pressurized gasare separately introduced into the enclosed volume with inert gas beingintroduced into the enclosed volume prior to and subsequent introductionthereto of each of the one or more pulses of the first pressurized gasand the one or more pulses of the second pressurized gas.
 5. The coatingsystem of claim 3 comprising the plurality of first pressurized cells,the plurality of second pressurized cells, or both the plurality offirst pressurized cells and the plurality of second pressurized cells.6. The coating system of claim 5, wherein the controller is configuredto alternate introduction of one or more pulses of the first pressurizedgas with one or more pulses of the second pressurized gas.
 7. Thecoating system of claim 2, wherein the first pressurized gas consists ofthe one or more first reactant gases, or wherein the first pressurizedgas further comprises from about 10 to about 90 volume percent (vol %)of a first buffer gas; and/or wherein the second pressurized gasconsists of the one or more second reactant gases, or wherein the secondpressurized gas further comprises from about 10 to about 90 vol % of asecond buffer gas, wherein the first buffer gas and the second buffergas are the same or different.
 8. The coating system of claim 1 furthercomprising: a plasma source fluidically coupled to the housing toprovide plasma for the one or more surface coating processes; an ionsource fluidically coupled to the housing to provide ions for the one ormore surface coating processes; a heating unit in thermal communicationwith the housing to heat the housing for the one or more surface coatingprocesses; or any combination thereof, wherein the controller is furtherin electronic communication with the plasma source, the ion source, theheating unit, or the combination thereof to control the plasma source,the ion source, the heating unit, or the combination thereof during theone or more surface coating processes.
 9. The coating system of claim 1further comprising: a heater; and a drying gas source, wherein theheater is in thermal communication with the drying gas source, thehousing, and/or a line fluidically coupling the drying gas source andthe housing such that a hot drying gas can be provided within theenclosed volume to dry the interior surface of the housing prior tointroduction of any of the one or more first reactant gases or the oneor more second reactant gases thereto.
 10. The coating system of claim9, wherein the controller is in further electronic communication withthe heater and/or the drying gas source to control the heater, and/orthe drying gas source during the one or more surface coating processes.11. The coating system of claim 10 further comprising one or more pumpsupstream or downstream of the housing, wherein the one or more pumpsinclude a vacuum pump on at least one of the one or more first flowlines, a vacuum pump on at least one of the one or more second flowlines, or both a vacuum pump on at least one of the one or more firstflow lines and a vacuum pump on at least one of the one or more secondflow lines, wherein the vacuum pump is configured to create a vacuum inthe enclosed volume during drying, whereby the one or more first flowlines or the one or more second flow lines having the vacuum pump canoperate as a vacuum line.
 12. The coating system of claim 11 furthercomprising a moisture detector on the vacuum line, wherein the moisturedetector is operable to measure a moisture content of the hot drying gasremoved from the enclosed volume during the drying.
 13. The coatingsystem of claim 1, wherein the coating system is operable for coatingthe interior surface at a coating temperature of room temperature, acoating pressure of atmospheric pressure, or both a coating temperatureof room temperature and a coating pressure of atmospheric pressure. 14.A coating system for coating, with one or more surface coatingprocesses, an interior surface of a housing defining an interior volume,the coating system comprising: a first closure and a second closure tosealingly engage with a first end and a second end, respectively, of thehousing to provide an enclosed volume; a first flow line fluidicallycoupled to the first closure and a second flow line fluidically coupledto the second closure, wherein the first flow line, the second flowline, or both are fluidically connected to an inert gas source; one or aplurality of reactant gas sources, wherein the one or each of theplurality of reactant gas sources comprises a reactant gas and isfluidically coupled to the first flow line, the second flow line orboth; and a controller in electronic communication with the one or theplurality of reactant gas sources and the inert gas source, wherein thecontroller is configured to control flow of the inert gas from the inertgas source into the enclosed volume, and to control counter currentinjection of the reactant gas from the one or the plurality of reactantgas sources into the enclosed volume such that introduction of one ormore pulses of the reactant gas into the enclosed volume are separatedby introduction of the inert gas into the enclosed volume, and one ormore coating layers are deposited on all or a portion of the interiorsurface within the enclosed volume, wherein the one or more surfacecoating processes comprise chemical vapor deposition (CVD), atomic layerdeposition (ALD), or both.
 15. The coating system of claim 14 furthercomprising a sensor for monitoring a thickness of the one or morecoating layers, wherein the sensor comprises a sensor for measuring aconcentration of uneacted reactants passing out of the enclosed volume,a quartz crystal microbalance, or an optical monitor, wherein thecontroller is further in electronic communication with the sensor andoperable to adjust a duration of introduction of the one or more firstreactant gases and/or the one or more second reactant gases, an order ofintroduction of the one or more first reactant gases and/or the one ormore second reactant gases, a concentration of the one or more firstreactant gases introduced into the enclosed volume and/or of the one ormore second reactant gases introduced into the enclosed volume, or acombination thereof.
 16. The coating system of claim 14, wherein theinterior volume has an aspect ratio that is less than or equal to about0.5, wherein the aspect ratio is an average width of the interior volumedivided by an average length thereof.
 17. The coating system of claim14, wherein the housing comprises a well tool, wherein the well tool isa logging while drilling (LWD) tool, a measurements while drilling (MWD)tool, or a sampling while drilling (SWD) tool, and wherein a volume ofthe well tool defines a fluid flow path for flow of a formation fluidfrom an exterior of the well tool through an interior of the well tool.18. A coating system for coating, with one or more surface coatingprocesses, an interior surface of a plurality of housings, the coatingsystem comprising: the plurality of housings, wherein the plurality ofhousings are connected in series and/or in parallel, wherein each of theplurality of housings comprise a first closure and a second closure tosealingly engage with a first end and a second end, respectively, of thehousing to provide an enclosed volume, and one or more first flow linesfluidically coupled to the first closure and one or more second flowlines fluidically coupled to the second closure; wherein the second flowlines fluidically coupled to each of the plurality of housings arefluidically coupled as the first flow lines to any immediatelydownstream housing, and wherein the one or more first flow lines, theone or more second flow lines, or both are fluidically connected to aninert gas source; one or a plurality of reactant gas sources, whereinthe one or each of the plurality of reactant gas sources comprises areactant gas and is fluidically coupled to the one or more first flowlines, the one or more second flow lines or both; and a controller inelectronic communication with the one or the plurality of reactant gassources and the inert gas source, wherein the controller is configuredto control flow of the inert gas from the inert gas source into theenclosed volume, and to control counter current injection of thereactant gas from the one or the plurality of reactant gas sources intothe enclosed volume of each of the plurality of housings such thatintroduction of one or more pulses of the reactant gas into the enclosedvolume are separated by introduction of the inert gas into the enclosedvolume, and one or more coating layers are deposited on all or a portionof the interior surface within the enclosed volume.
 19. The coatingsystem of claim 18, wherein the plurality of housings are connected inseries, wherein each of the plurality of housings except a last housingof the series of housings is fluidically coupled with an immediatelydownstream housing via a U-shaped connector.
 20. The coating system ofclaim 19, wherein one or more of the U shaped connectors are fluidicallycoupled with one of the plurality of first reactant gas sources and/orone of the plurality of second reactant gas sources, whereby the one ormore first reactant gases and/or the one or more second reactant gasescan be injected into the one or more U-shaped connectors and therebyintroduced into the interior volume of a housing immediately downstreamof the one or more U-shaped connectors.